Yesterday a 2009 Chevrolet Malibu with a 2.4-liter dual overhead camshaft with Variable Camshaft Timing (VCT) rolled into the shop. The customer’s complaint was the “Check Engine” lamp was on. I retrieved trouble codes P0010 (Camshaft Position Actuator Circuit Open – Bank 1) and P0011 (Timing Over-Advanced Bank
1). Looks like we have a VCT Actuator problem.
VCT camshafts are controlled electronically by actuators that direct high pressure engine oil into camshaft phasers. The phaser then advances or retards the camshaft up to 30 degrees by rotating the camshaft from its base position. Some VCT benefits are increased engine perf o r m a n c e , increased fuel efficiency and lower emissions. In addition, engines that use VCT technology for the exhaust camshaft do not require exhaust gas recirculation valves. Retarding the exhaust camshaft achieves the same net result.
What is the function of the VCT actuator? It’s a gate. When it’s open, oil passes freely into the phaser. When it’s closed the flow of oil is blocked. The actuator movement is controlled by the actuator solenoid. TECH TIP. Before I continue, I would like to discuss oil viscosity. Simply put, viscosity is the oil’s resistance to flow. The higher the viscosity (50 weight) the slower it flows. If the oil flows too slowly it can adversely affect the operation of the hydraulic phasers and actuators. Thicker oil, dirty oil or low oil can all cause engine performance problems and set trouble codes. WARNING! Only use the oil that is the correct viscosity for your engine.
Our code is an electrical circuit code so I’m not concerned with the oil. One of the VCT diagnostic tests asked me to perform a resistance check of the actuator solenoid. That means disconnecting the solenoid’s electrical harness so I can connect an ohmmeter to the solenoid’s two electrical terminals. The specification is 5-9 ohms of resistance at ambient temperature. No way am I doing that test. Old school! I want to test the complete circuit intact. Testing of engine components and circuits should be performed at operating temperature and during operational stress. The better test is to use a Lab Scope and Low Current Amp Probe. According to Ohm’s Law, if I divide 12 (system voltage) by 9 (resistance specification) the current (flow of electrons) will be 1.3 amps. The Current Amp probe will measure the circuit’s current. Our solenoid has only two wires: power and ground. Since current flow is identical throughout the entire circuit it doesn’t matter which wire I test. I placed my Current Amp probe around one of the wires and activated the solenoid. Zero current. That’s it, we found the problem. The Intake VCT actuator solenoid is defective open. Just to back up my test, I also tested the identical actuator solenoid for the exhaust camshaft. Perfect – 1.3 amps.
A few months back a Subaru Outback came into the shop. The transmission had a heavy shudder when driving away from a stop. Unknown to me, she had been to several other shops prior. All recommended the replacement of the transmission at a cost of about $10,000. The transmission module was under the dash and easy to access. I placed my Current Amp probe around the single blue Torque Converter Clutch (TCC) Solenoid driver circuit and test drove. There it was. The Subaru TCC solenoid failure was the opposite of the Malibu VCT solenoid failure. The TCC solenoid was shorted to ground so the current was very high. Easy fix at 1/8 the cost. Just for fun I decided to test both of the Malibu VCT solenoids “Old School” with the ohmmeter. You guessed it, both PASSED at SAY YOU SAW IT IN the exact same value. Ten years ago, I would have been stumped at this point. I would have eventually fixed the Malibu but it would have taken longer and required an educated guess. Armed with a Lab Scope and a Low Current Amp probe, both vehicles were simple. Fixed the cars, got paid, no problem.
As I was considering this article, it occurred to me this advanced diagnostic testing is something 93636 “Do it yourselfers” can do for a relatively low investment. There is a high quality single channel Lab Scope about the size of my cell phone available for around $170. It’s called “Uscope.” Google or YouTube “Uscope” and check it out. The “Low Current Amp” probe is about $80. Both are manufactured in Fresno by AES Wave. We use ours all the time. A Uscope would be the best belated Christmas gift of all time. Just saying.
Vehicles are loaded with all kinds of solenoids, from fuel injectors to power door lock actuators. You can also test your vehicle’s many electric motors including the windshield wiper motor, the heater blower motor and electric fuel pump motor just to name a few. The testing procedures are exactly the same as used in this article. The waveforms are different but I can help you with that. That’s all for now.
As always, I’m looking for topics to write about. If you have a suggestion or question concerning a vehicle, please contact me at email@example.com or Facebook me at Complete Car Care.
God Bless the United States of
America and God Bless 93636.
2013 & 2014 NAPA/ASE California
Technician of the Year
The Frequency of Noise
Today I would like to tell you about a recent occurrence that happened at my shop and how a new technology developed in Europe saved the day. Before that I would like to take a brief moment to speak to the 93636 females who maybe reading my “In Good Hands” column. Ladies, you represent 70 percent of the goods and services purchased from my industry. Please, don’t hesitate to contact me. I would love to include and answer your questions in future articles.
Last month a new customer came into the shop complaining of an intermittent popping noise during braking and/or acceleration. His vehicle was involved in a front-end collision and the noise began after the vehicle repair.
Not The Best Start
This is definitely not the kind of diagnostic I would prefer when beginning a new customer relationship. Modern vehicles have so many components crammed into tight spaces, especially under the hood, it’s extremely difficult to detect the cause of unwanted noises. Noises echo and resonate. Hollow components act like megaphones. Vehicle noises, especially intermittent noises, are among the most difficult complaints to solve. This vehicle is a luxury vehicle and a misdiagnosis or incorrect guess would be very expensive. Most of you know by now that I constantly preach about my dislike for guessing. Testing is much more efficient. Automobiles are engineered by human beings using math and science. Therefore, math and science hold the solution to our diagnostic.
Recently I attended two NVH (Noise, Vibration, Harshness) training classes designed to aid in the diagnostic of noise, vibration and harshness complaints. The new Pico technology uses remote sensors (accelerometers), software, a microphone and laptop to measure and locate the sources of NVH complaints. When the sensors retrieve sounds and/or vibrations, the technology creates a waveform on the laptop screen. The taller the waveform the more harsh or closer the sound or vibration source is. The technology also displays the waveform’s oscillations indicating the frequency of the noise. The closer the oscillations, the higher the frequency.
Making Sense of Frequency
When driving down the road, the engine assembly, drive shaft assembly and tires are all rotating at different speeds or frequencies. Let’s do the math at 60 miles per hour. If the circumference of a tire measures 72 inches (6 feet), we divide 6 feet into 5,280 feet (one mile) and our tire rotates 880 times per mile or 14.66 rotations per second (14.66 Hz). If the differential gear ratio is 3:33, the transmission output shaft and drive shaft rotates three times for every one rotation of the wheel, or 45 Hz. At 1,800 rpm, the engine is rotating 30 times per second or 30 Hz. At 60 miles per hour, the wheel speed is 15 Hz, the drive shaft speed is 45 Hz and the engine speed is 30 Hz. It’s a math problem. The NVH module is connected to engine RPM and we program in the differential gear ratio and tire size. The NVH does the calculation and determines the potential causes based on frequencies. In this example, if our undesired noise is measured at 15Hz, we have narrowed our focus to components (tire, wheel bearings, brake rotor, axle, carrier bearings and ring gear) connected to the wheel. By moving the sensors around, we can zero in on the location of the vibration. The NVH technology can also differentiate between simultaneous vibrations occurring from different component assemblies.
In our case, we were attempting to locate a popping noise which requires a little different diagnostic process. We placed one sensor on the driver’s seat rail and the other near SAY YOU SAW IT IN the collision repairs. When the pop occurs the sensor nearest the noise creates the tallest waveform. We just kept moving the sensors until they were one foot apart. In between were a lower control arm bushing and a body mount bushing. To determine which bushing was defective, we placed the sensors on the inside and outside of each. A bushing consists of three parts: the outer steel ring, the smaller inner steel ring and the rubber cushion in-between. The rubber cushion is designed to absorb vibrations, not transfer them. If our sensor waveforms are similar, the rubber failed to absorb. If the waveforms are dissimilar the rubber was successful.
We found it.
The body mount was our cause. The new technology put us right on the problem with no mistakes. It is much more fun being an automotive technician today than at any time in my past.
The technology does come with a steep learning curve and my explanation may be an over-simplification but no guessing is required. That’s all for today. Hope this article is informative and helpful.
As always, I am looking for interesting things to write about so I would appreciate any input, suggestions or questions you may have concerning your automobile or the automotive industry. I can be contacted at complete_car_care @hotmail.com or Facebook me at Complete Car Care.
God bless the United States of America and God bless 93636.
2013 & 2014 NAPA/ASE California
Technician of the Year
Boosting the EcoBoost
March was a very busy month for me with lots of automotive training classes. It started with a Ford EcoBoost Class, followed by a Cummins diesel class and finally a waveform class, my favorite.
Before I begin, I’m asking you ladies for your input concerning topics for this column. In the automotive repair industry, you ladies purchase 70 percent of our goods and services. What information would be valuable to you when purchasing your next service or repair? Your input would be appreciated.
Today I would like to start with some fun details from the Ford EcoBoost class. The EcoBoost family of engines has added 128 new patents to Ford’s development portfolio. As a result of this new technology, the 2.7L EcoBoost V6 engine introduced in the aluminum frame F-150 pickup truck produces 325 horse power (hp) and 375 foot pounds of torque. WOW! A 166-cubic inch (ci) engine producing 325 hp.
The 3.5L (214ci) EcoBoost V6 engine uses twin intercooled turbochargers to produce the equivalent power produced by its V8 predecessor while obtaining a 15 percent increase in fuel mileage. Ford’s second generation 3.5L EcoBoost V6 is expected to produce 600 horse power in the Ford GT.
These EcoBoost engines are very small when compared to the engines from the recent past. These smaller engines and Direct Fuel Injection equate to increased fuel efficiency and lower CO2 exhaust levels. The big horsepower comes from the introduction of turbocharging and the reduction of “Pumping Loss.” What the heck is “Pumping Loss”? I’ll discuss that later in the article.
As a point of interest, what Ford and other automotive manufacturers are now doing is not new. The Offy racing engine was doing this at least 70 years ago. Those small 4-cylinder turbocharged engines dominated the Indianapolis 500 with 24 victories in 27 years. The 3.0L dual overhead camshaft, four valves per cylinder Offy’s produced more than 800 hp. The big difference is, EcoBoost engines are computer controlled. They can make big horsepower on demand or transform into a meek, mild, fuel efficient little guy on the way to the grocery store.
The new Ford EcoBoost technology presents some very unique diagnostic challenges for us. It appears that many of our standard baseline diagnostic tests may not work. I’m hoping there is a way to defeat the computer control and place these systems into a conventional mode for testing purposes. Going to be a steep learning curve ahead. I was very apprehensive at first but after some contemplation, I realize this is just some very cool engineering and science and nothing to be afraid of. We are looking forward to the challenge.
In order to prepare ourselves, we will rent an EcoBoost vehicle for the weekend and connect all of our technology and see if it’s applicable. We will also record known good data for our diagnostic baseline library.
What is “Pumping Loss”? Gasoline engines have it and diesel engines don’t. A gasoline engine regulates the amount of air entering the engine cylinders by blocking the air inlet passage with a throttle valve. The throttle valve is like a gate. When it’s closed at idle, it greatly restricts the amount of air (oxygen/fuel) entering the engine’s cylinders. When the gate opens by pushing on the gas pedal, the restriction is decreased. The increased air flow results in increased power. A closed throttle valve creates the “Pumping Loss” inefficiency. Here’s why: When the engine’s pistons move downward, air is drawn into the cylinders to fill the voided areas. Because of the air restriction, a high-pressure area is created in front of the throttle valve and low pressure area behind the throttle valve. Think of a dam blocking a river. Lots of water pressure above the dam but nothing below. That low pressure or vacuum is a very powerful force and requires a greater force to overcome it or the engine will stall. Up to 30 percent of the power generated by a gasoline engine is lost overcoming the vacuum created by the throttle valve.
The energy required to overcome the vacuum is called “Pumping Loss.” So how do we eliminate pumping loss? Easy! Eliminate the throttle valve. The EcoBoost strategy to decrease the amount of air entering the cylinders is to delay the opening of the intake valve. When the intake valve opening is delayed, the opportunity for air to enter the cylinder is reduced. The technology used to accomplish that delay is Variable Camshaft Timing. Variable Camshaft Timing technology was the topic of my January 2017 article entitled “Actuator Action.” It can be accessed online through the Ranchos Independent’s archives. There are some valuable tech tips in that article that will help you correctly maintain your EcoBoost engine. Variable Camshaft Timing eliminates the necessity for a throttle valve.
The introduction of the turbocharger is another important component in the elimination of “Pumping Loss” by pressurizing or boosting the air entering the cylinders. During boost, there is NO low pressure and NO vacuum to overcome. The turbocharger eliminates “Pumping Loss.” Hope this helps.
This year’s Flatlanders Day event will be held on Saturday, May 13. We will have some of our automotive diagnostic equipment present and connected to live vehicles. What diagnostic equipment or testing would you like us to demonstrate? Would you like a handson opportunity to use the hand-held UScope? Suggestions would be greatly appreciated. Students, if you are considering the automotive field for your career path, come and hang out. You will be our honored guests.
As usual, I’m looking for automotive topics and items of interest to write about. If you have any automotive questions or suggestions, I can be reached at firstname.lastname@example.org or Facebook Complete Car Care.
God Bless America and God Bless 93636.
2013 & 2014 NAPA/ASE California
Technician of the year.
When to Convert the Converter
Recently I received a rash of 93636 residents with emissions failures for which the catalytic converters where wrongly identified as the cause. Catalytic converter repairs can reach many thousands of dollars and a misdiagnosis can be very costly. I am writing this article so that anyone who follows this simple procedure will never become a victim of an incorrect catalytic converter diagnosis.
In theory, catalytic converters should last the life of the vehicle. Although it has no moving parts, it efficiently and effectively accelerates the chemical reactions within the converter without itself being affected. There is an internal “ceramic structure wash” coated with three different catalysts housed inside a steel outer shell. In my opinion, converter failures are a symptom of a cause, but not the cause itself.
The job of the converter is to convert harmful pollutants into harmless gasses before they exit the vehicle’s tailpipe. A properly functioning converter stores free oxygen. When hydrocarbons (HC) and carbon monoxide (CO) enter the converter, their bonds are broken and those compounds are reduced to their simple elements, hydrogen, carbon and oxygen. When the hydrogen and carbon atoms are reconfigured with the free oxygen atoms, carbon dioxide (CO2) and water vapor (H2O) molecules are formed, the same thing we humans exhale. It’s just chemistry.
There are two primary causes of converter failure apart from fuel contamination. Both causes stem from poor vehicle maintenance. Failure to maintain the engine’s secondary ignition system (tune up) is a recipe for misfires. Failure to maintain the engine’s fuel system increases the potential for under- or over-fueling. In either case, higher emissions are the result. The increased heat developed from the conversion of those emissions can overheat and destroy the converter.
The second cause of converter poisoning comes from another emission system: positive crankcase ventilation (PCV). When the engine’s piston rings wear and they lose their sealing capabilities, combustion leaks into the crankcase. The PCV system vents those crankcase vapors and other oil vapors into the air inlet system. The inlet air carries those vapors through the cylinders and into the exhaust. When the oil vapors coat the catalyst and it is no longer in direct contact with the emission gasses, the catalyst process is interrupted and the converter is inefficient. (Note: When you check your vehicle’s engine oil level and it’s no longer at the full mark, that missing oil passed through the catalytic converter unless it leaked.)
Do-it-yourselfers: only use the correct oil for your vehicle. Also, a good vehicle maintenance program does not cost, it saves money. Clean, fresh oil of the correct viscosity prevents wear, helps maintain the integrity of the engine’s internal seals and decreases oil consumption.
Since the introduction of On Board Diagnostics II (OBDII) in 1996, catalytic converters have pre- and post-oxygen sensors. These sensors measure the free oxygen entering and exiting the converter. If the converter is storing oxygen properly, the amount of free oxygen exiting the converter will be much lower than the amount entering the converter. If the pre- and post-converter oxygen sensor output values are similar, it is inferred the converter is not storing oxygen and is therefore inefficient. I often use the oxygen sensor’s algorithm to confirm an inefficient converter.
Do-it-yourselfers there is another way to diagnosis a defective catalytic converter and it’s something you will have no problem doing. My preferred diagnostic procedure to verify a catalytic converter failure is using a “Lambda Calculator.” The Lambda Calculator is one of the most powerful emissions diagnostic tools I have in my shop. I use this method more than any other because it’s simple, it’s extremely accurate and it’s FREE when you go online to SmogStats.com. If you failed an emissions test, simply enter the five tailpipe gasses (CO2, O2, HC, CO and NO) into the corresponding calculator box and push the calculation button. The lambda (air/fuel ratio) and catalytic converter efficiency results will be displayed. If you failed an emissions test and you were advised to replace your converter, STOP! Use the free calculator and you will NEVER guess and mistakenly replace a good converter.
The most important calculation is the lambda calculation. Here’s what you need to know with regard to the lambda calculation: 1.000 means the air to fuel ratio is perfect. Exactly enough oxygen was provided to completely burn all of the fuel and no oxygen or fuel was left over to produce emissions. The closer the lambda calculation is to 1.000 the more likely the fuel injection system is functioning well and is not the cause of the emissions failure. If the calculation is less than 1.000, an over-fueling condition exists. If the calculation is greater than 1.000, an under-fueling condition exists. 0.985 means the system is 1.5% rich (.985 + .015 = 1.000). 1.015 means the system is 1.5% lean (1.015 – .015 = 1.000) It’s just math. A catalytic converter should not be replaced if the lambda calculation is not between 0.985-1.015. Fix the cause first,
not the symptom.
Do-it-yourselfers this is IMPORTANT!!! The vehicle’s exhaust system can NOT have any leaks. If false oxygen is scavenged into the tailpipe emissions sample, the calculation will be skewed and misleading. Check for exhaust leaks if the oxygen test value was greater the 0.50%.
The second calculation available with the Lambda Calculator is the catalytic converter efficiency calculation. It speaks for itself. Anything below 25% and I’m likely to recommend a converter replacement, but only if the lambda calculation is between 0.985 – 1.015. Hope this helps everyone. It has never failed me and I use it religiously almost every day.
I’ll see you all at the Flatlanders Celebration on Saturday, May 13. I will take a cut-away converter with its ceramic structure exposed.
If you have questions or comments, I can be reached at email@example.com or Facebook me at Complete Car Care.
God Bless America and God Bless 93636
ASE Master Certified
Smog Technician License
$500 in Your Pocket
I want to thank all of you that stopped by my Flatlanders Celebration booth and said, “Hi.” Your kind words and encouragement were much appreciated. It’s great to be among the 93636 family.
Today I would like to tell you about a great opportunity if you own a vehicle that failed or may fail its tailpipe emissions test. As most of you know, I’m not a fan of big government handouts. The program I’m writing about is not a government program so it works well. If you would like some financial assistance getting your vehicle to pass its smog inspection, you are in luck. I whole-heartedly endorse this program. I personally know the managers and I’ve been partnering with these folks for more than five years. They are quality people and they care about the environment and the people of the Central Valley.
The organization I’m speaking of is Valley Clean Air Now, or “Valley CAN.” Valley CAN is a 501(c)(3) nonprofit organization that partners with more than 100 local organizations and more than 50 STAR-certified smog check stations throughout the San Joaquin Valley. Valley CAN serves the eight economically and environmentally impacted counties of the San Joaquin Valley Air Basin. Valley CAN serves 3 million residents and their 2 million vehicles by providing financial assistance along with the opportunity to help improve Valley air quality. Each year Valley airborne particles exceed federal standards for about five days, but California’s standard is much tighter so the Valley exceeds California’s standard an average of 90-100 days per year. Approximately 27 percent of air pollution in our North Valley is transported from the San Francisco Bay and Sacramento areas. It’s estimated that San Francisco and Sacramento areas contribute about 11 percent to our air pollution. Valley CAN’s mission is to improve air quality within the San Joaquin Valley Air Basin.
One of the programs utilized by Valley CAN is the Tune In & Tune Up (TITU) program. The primary focus of the Tune In & Tune Up program is contained within its name. The TITU program focuses on “out of tune” or “poor running” vehicles. They produce the most tailpipe emissions that negatively impact air quality. TITU events provide free emissions testing to determine if a vehicle qualifies for free emission repairs. If your vehicle fails its tailpipe emissions testing, Valley CAN will give you a $500 voucher for emission-related repairs from one of many local STAR-certified smog stations listed on the voucher. Valley CAN holds many TITU events each year and the next local event should occur within the next couple of months.
As a STAR-certified Smog Check Station myself, I am required to perform a pre- and post-repair tailpipe emissions test to verify the emissions improvement. If my repairs do not significantly improve the vehicle’s tailpipe emissions, my invoice will be rejected. Testing and repairs performed with the TITU program are the same quality repairs as customer-paid repairs. “Check Engine” lamp and other emission failures that do not improve tailpipe emission are not covered by the TITU program.
Since its inception in 2003, more than 15,000 vehicles have been repaired to California emissions standards with the aid of the TITU program. A typical event tests an average of 500 vehicles. Repairs resulting from one TITU event equate to the removal of approximately 3,000 tons of carbon monoxide, 300 tons of hydrocarbons and 150 tons of oxides of nitrogen from the air for one year. To date, TITU is among the most cost-effective emissions reduction programs in California. If you’ve owned your gasoline-powered vehicle for six months or more and it’s a light or medium duty vehicle (weighs less than 14,000 pounds), you qualify. Event days are Saturdays and testing officially starts at 8 a.m. but usually begins earlier. It’s wise to arrive at least 3 hours prior. Take a book. $500 is $500. Take your registration. If you don’t have a registration, take whatever documents you have (title, insurance paperwork, an invoice from a repair shop). When my customers fail the tailpipe emissions portion of their emission test, I always inform them of the TITU program. I’m guessing I’ve save my customers at least $50,000 dollars or more. It works!
If you have any questions concerning Valley CAN or Tune In & Tune Up events, contact valleycan.org or give me a shout. We are here to help.
As usual I’m looking for useful and interesting automotive topics to write about. If you have any suggestions or questions concerning a vehicle, I can be contacted at firstname.lastname@example.org or Facebook me at Complete Car Care. OK everyone, hope this helps.
In closing I’d like to make a personal plea to my 93636 family. Someone told me a long time ago he had no sons-in-law and daughters-in-law, only sons and daughters in his family. I think that’s right. My daughter Renée and her husband Jon are currently home on leave from Okinawa, Japan. It’s been 1 1/2 years since I’ve seen my kids and my grandchildren. In two weeks they return to base. If the United States and North Korea enter into conflict, Renée and my grandchildren will be evacuated to the U.S. and my son Jon will go to the battlefield again. He’s been in combat twice in Iraq and twice in Afghanistan. Jon is a United States Marine Corps gunnery sergeant. Please pray the U.S. and North Korea can resolve our conflict peaceably. Thank You.
God Bless 93636 and God Bless America,
Warren Parr, Smog Inspector License
Keep it Cool
Lots of update training during the months of May and June. The training that stands out most in my mind is the training I received concerning today’s complex vehicle cooling systems. But before that I have an update for May’s “In Good Hands” article. Local TITU (“Tune In Tune Up”) events will be held on July 15 at the Chowchilla fairgrounds; Aug. 26 at the Fresno fairgrounds; and Nov. 11 at the Madera fairgrounds. There is no downside to this program. There is no income eligibility qualification and no cost. If you are concerned your vehicle’s tailpipe emissions may be higher than your vehicle’s Smog Check Pass threshold and would like financial assistance, be there. Your vehicle’s tailpipe emissions will be evaluated on site. If your vehicle has already failed a smog inspection due to excessive tailpipe emissions, you qualify. Take your failed test report with you. For more information go to valleycan.org or give me a call. We will be glad to walk you through the process. It’s easy.
I know I talk a lot about emissions but emission reduction is the driving force behind the complexity of today’s vehicles. For that reason, today’s engines run very clean except during cold starts and warm up. In order to reduce those emissions, today’s cooling systems have been redesigned. That’s correct, the cooling system is now part of the emissions system. The goal is to reach normal operating temperature within 90 seconds after a start up from 40 degrees Fahrenheit. The correct engine warm up rate is 0.2 – 0.4 degrees F per second. Failure to meet this standard will result in lower tailpipe emissions reduction and “Check Engine Light” illumination.
Decreasing engine warm up time is accomplished using a variety of methods. One is to decrease cooling system capacity. Less fluid requires less time. Some cooling system capacities are as little as five quarts. The loss of just one quart is the loss of 20 percent of the system’s cooling capacity. No margin for error. Because of the different expansion rates (aluminum 1.7 times greater than iron) of the dissimilar metals used in the production of today’s engines, a gasket sandwiched between dissimilar metals can lose its seal due to shearing. Be careful. No overheating please. Replacing head gaskets on a variable cam timing, dual-overhead camshaft, direct-fuel injected, turbocharged engine is no easy task.
The introduction of computer controlled grille shutters is another way. The shutters, behind the front grille, serve several purposes. Closing the shutters blocks ambient air flow through the radiator and thereby decreases engine warm up time. The shutters are also used to regulate air flow through the radiator and maintain optimum engine operating temperatures (195 F- 212 F) during all phases of driving. An additional benefit from grille shutters happens when the shutters are closed as much as possible while driving. Closing the shutters decreases the vehicle’s drag coefficient and improves fuel mileage.
Another option to decrease engine warm up time is to circulate engine coolant through the exhaust system. Coolant is diverted into exhaust manifold passages where exhaust heat is radiated into the coolant. When the engine coolant reaches its pre-set temperature, the exhaust coolant passage is closed. Maintaining today’s cooling systems is critical to the proper function and operation of the engine and tailpipe emissions reduction.
At the heart of your vehicle’s cooling system is its water pump. Today’s typical eight-cylinder engine water pump moves 80 gallons of coolant per minute. Imagine that. These water pumps are capable of draining the average swimming pool (25,000 gallons) in slightly more the five hours. This increased efficiency can be attributed to the use of plastic impellers with exotic blade designs.
Some impellers are constructed from Nylon 66. Nylon 66 is incompatible with some coolants/antifreezes. If the incorrect coolant is used during service, impeller failure is eminent. It may take a few years but the impeller will slip on the impeller shaft and then break apart. This also applies to plastic radiators and intake manifolds. The chemistry of today’s cooling systems is also CRITICAL. The days of one size fits all engine coolant is long gone.
A major factor to consider for the proper maintenance and longevity of today’s cooling systems is the pH level of the coolant. When the pH drops below 8.5, the corrosion rate of cast iron increases. When the pH is above 11 the corrosion rate of aluminum increases. The proper pH range for a modern cooling system is 9.8-10.5. The problem is the pH of water is 7.0. The pH of ethylene glycol, the main ingredient in most antifreeze/coolants, is 10.5. At a 50/50 mix the coolant pH is 8.75 and short of our 10.1 target. It is important to supplement the cooling system with a pH buffer. It’s just chemistry.
It’s easy to measure pH. Dip a pH test strip into the engine coolant and watch it change color. Compare the test strip color to the baseline scale on the side of the test strip container and read. I purchase my test strips from NAPA and I will be glad to give you one. Just let me know.
Ethylene glycol does not wear out but the lubricants, silicates, phosphates and other coolant additives do. Be proactive. Exchange your vehicle’s coolant at the manufacturer’s recommended intervals. Preventative maintenance does not cost. It saves when done properly.
My preferred method for servicing a vehicle’s cooling system is a reverse cooling system flush. Compressed air pulses the coolant which causes a scrubbing action and vibrates debris loose. Flushing the old coolant in the reverse direction pushes debris out of the cooling system and into the machine to be discarded. “Drain and Fill” does not remove much debris.
Do-it-yourselfers, my advice is do not attempt to service the cooling system of a modern vehicle without proper training and equipment. At times, however, you may want to top off your cooling system. Never ASSUME what type of coolant to use. If in doubt, do what I do. Purchase the correct coolant from the dealer. In an emergency, use water. It’s compatible with all coolants.
When servicing the cooling system of an old school vehicle, keep the following principles in mind and all should be fine:
• Never EVER EVER mix coolants. The color of the coolant is NO indicator of the coolant type.
• NEVER use tap water. Use distilled water only. As you can imagine, the introduction of iron, sand and other debris into the cooling system acts like sandpaper on water pump impellers and other cooling system components. Adding fluorine, chlorine and who knows what else into the cooling system changes the cooling system chemistry. Mix the coolant and distilled water at 50/50.
OK everyone, that’s all for today. Hope this helps. Ladies, thank you for your input and encouragement. It’s great. As always, we’re looking for informative and interesting automotive topics to write about. If you have any suggestions or questions concerning a vehicle, I can be reached at email@example.com, Facebook or text at 559-907-7661.
God Bless America and God Bless 93636.
ASE Mastercertified and Advanced
Level Technician since 1988
NAPA/ASE 2013 & 2014 California
Technician of the Year
A “Current” Affair
I chose this article’s topic because it’s very unique, intriguing and reinforces several points I’ve been trying to make through the writing of this column.
Last week I received a phone call from a customer that was considering replacing his vehicle’s HVAC control module (Heating, Ventilation & Air Conditioning microprocessor). He wanted to know if we had the capability to program the new module or should he take his vehicle to the dealer. My experience with customers inquiring about replacing modules is that it’s the only thing left that hasn’t been replaced. Just to make this article more interesting, my customer is a Madera County elected official. I know he does not have the equipment to properly diagnose a defective module. I asked him about his complaint and if any HVAC module diagnostic trouble codes were retrieved. NO and his complaint was the air conditioning intermittently stops blowing cold. Because it’s intermittent, he thought it was the controller. It wasn’t.
First Point: Guessing, or the Trial and Error Method, is the most expensive way to diagnose an automotive problem.
Naturally for us, the customer’s complaint was not present when the vehicle arrived. The AC system appeared to be working properly. No problem. Scott, my lead technician, began his diagnostic by retrieving a trouble code stored in the suspect HVAC module. That code led him to start his diagnostic with the AC compressor. He performed his baseline tests so that when the failure did occur, that data could be compared to the failed test data. Good move Scott. The baseline test that eventually identified the failure and its CAUSE was a current flow test. The same test I’ve been preaching about for years. We simply place a small CURRENT AMP PROBE around the wire. When current flows, the current is displayed on the scope in a waveform. Easy-Peasy.
Second Point: “Do it Yourselfers,” my recent articles have contained a lot of warnings and “do nots.” This article is about a DO. With a current amp probe, you can’t hurt the vehicle, yourself or the equipment, unless you stick your fingers and/or drop the equipment into the cooling system fan while it’s turning.
A little refresher course at this point may be useful. First: Current is the flow of electrons. Current is measured in amps. When electrons flow through an electrical component, that component performs work. The more electrons that flow (current), the more work being performed. Second: Electrical current is equal throughout a circuit. Therefore, the current probe can be placed anywhere (easiest) on the wire/circuit. Third: Since we are only concerned with the amount of current and not its direction, it doesn’t matter if we place the probe backwards or forwards. We can’t mess up.
Most automotive AC compressors have just two wires: current, coming and going. They are used to energize the AC compressor clutch coil. The AC clutch coil is that big black round thing on the front of the AC compressor just behind the serpentine belt. Inside the clutch coil cover is a long coil of copper wire; if stretched out it would measure a half mile or so. When electrical current flows through a coil of wire, it creates a magnetic field. The larger the coil, the greater the magnetism. When energized, the magnetism of the AC clutch coil attracts and holds together both steel clutch plates so the serpentine belt can spin the AC compressor.
The Diagnostic OK, back to Scott’s diagnostic. When our AC was functioning properly, the clutch coil current measured 1.5 amps. When the AC failed, the current increased to 8 amps. Let’s do a little math using Ohm’s Law. If we divide our voltage (12.5 volts) by our current (1.5 amps), we know our resistance to current flow is 8.33 ohms when the AC system is functioning properly. At failure, the current increased to 8 amps. By re-doing the math, we can see the resistance to current flow decreased by 80 percent. What happened that caused the resistance to electron flow to suddenly decrease? Heat distorts things.
When the insulation barrier separating the coil of copper wire from its steel cover flexed enough, the steel cover became the conductor that provided the electrons a short cut to ground (path with the least resistance). Since the electrons didn’t have to drudge through the entire 1/2 mile of wire, current flow (amps) increased because the resistance to flow decreased. We have a short to ground.
When the HVAC module saw high current, it went into protective mode and turned the AC off, set a trouble code and ignored the driver’s request for AC. The module DID ITS JOB. Testing saved about $400.
Madera Ranchos “Do it Yourselfers,” this test works for all coils, including ignition coils and solenoids like fuel injectors, transmission shift solenoids and electric door lock actuators. The only thing preventing you from doing this diagnostic is a single channel lab scope and a current amp probe. Google “uScope Master Kit.” It’s very inexpensive.
When researching the vehicle’s records, we discovered we installed the AC compressor assembly three years ago. OK. What’s the manufacturer’s warranty? You guessed it … two years. At this point I became an advocate for my customer. The waveform showed the coil was defective and not due to abuse. When we called my NAPA salesman, it just so happened the AC compressor manufacturer’s representative was in town and they drove right over. Scott walked the representatives through the waveform point by point. Because a current amp probe waveform is so easy to understand, they agreed the coil was defective even though this was their first current waveform. On the spot they warrantied the AC compressor assembly. Our defective coil and its waveform is being returned to the manufacturer for further testing and evaluation.
Third Point: This is the American free enterprise system. Industry working with industry for the benefit of the American people. I am proud of our automotive aftermarket parts industry. I’m proud of our automotive diagnostic equipment manufacturers and trainers that give us, working in the field, the tools and training to accurately diagnose and repair vehicles and collaborate with our parts manufacturers to improve product quality, reliability and customer satisfaction. I’m proud of my parts supplier, NAPA, for going the extra mile.
That’s all for now. I hope this helps. As always, I’m looking for interesting automotive topics to write about. If you have any automotive or automotive industry questions or want to send me your waveform, I can be contacted at firstname.lastname@example.org, Facebook Complete Car Care or text me at 559-907-7661.
God Bless America and God Bless 93636,
A 2013 & 2014 NAPA/ASE California
Technician of the Year.
A 2013 NAPA/ASE National Technician
of the Year 2nd Runner UP.
Car, Drive Thyself
Lots of training this month (Brake/Anti-Lock class, Hybrid High Voltage Class and GM Duramax Diesel Class). A spontaneous and very interesting discussion was generated during the Anti-Lock/Crash Avoidance portion of the Brake Class. I thought the Ranchos Independent readers might also be interested in our discussion so I did a little Google research to add some detail. I was surprised how many do not know about Google’s autonomous vehicles.
In 2015, Google announced their 23 self-driving vehicles had driven over 1 million miles, encountered 200,000 stop signs, 600,000 traffic lights, and 180 million other vehicles. As of July 2015, those vehicles have been involved in 14 minor collisions on public roads. Based on Google’s own accident reports, human drivers were at fault 13 times. Eight times Google’s vehicles were rear-ended at a stop sign or traffic light. It was not until 2016 that a Google car’s software caused a crash. That occurred in February, 2016 when a Google selfdriving car attempted to avoid sandbags blocking its path. During the maneuver, it made contact with a bus.
In the United States annually, 42,000 people are killed and more than 2.7 million people are injured in traffic accidents. According to Corey Harper of Carnegie Mellon University (the Autonomous Vehicle Research hub), “… widespread implementation of blind-spot detection, lane departure and forward collision warning technologies could prevent or reduce the severity of as many as 1.3 million accidents, or about 25 percent of all crashes [annually in the U.S.]”
In the recent past, automotive manufacturers have focused on enhanced onboard safety features like anti-lock braking systems, air bags, side air curtains, vehicle to vehicle communications and structural designs to increase crash survivability. The industry’s new focus is on “crashavoidance technology” which attempts to avoid the crash all together.
It appears the original focus of self-driving vehicles was for use by the United States Military. The Defense Advanced Research Projects Agency (DARPA) annually sponsors competitions for American self-driving vehicles and pays cash awards. DARPA’s mission is to gain revolutionary, high-payoff research that bridges the gap between fundamental discoveries (civilian) and military use. The first DARPA contest was held in the Mojave Desert on March 13, 2004.
In 2005 the team from Stanford University created the robotic vehicle Stanley which won the 2005 DARPA Grand Challenge and its $2 million prize. The team that developed Stanley consisted of 15 engineers working for Google.
Fast forward to May, 2014. Google revealed its new prototype driverless car, which has no steering wheel, gas pedal or brake pedal. The prototype began its testing on San Francisco Bay Area roads in 2015. Google’s prototype cars have an estimated $150,000 in Crash Avoidance Technology on board, including a $70,000 LIDAR System. The range finder mounted on top of the vehicle is a Velodyne 64-beam laser. The Velodyne System allows the vehicle to create a detailed 3-D map of its environment. The system then takes those generated maps and combines them with high-resolution maps of the world, producing different types of data models that allow it to drive itself.
However, if you’re betting on Silicon Valley stars like Google, Tesla and Uber with autonomous driving technology, don’t. That’s the key takeaway from a new report. According to Navigant Research, whose newly released “leaderboard” report ranks players not just on their ability to make a car drive itself, but on their ability to bring that car to the mass market.
Ford – YES, Ford, that Detroitbased, 113-year-old giant – is winning the race to build the self-driving car, with General Motors running a close second. Renault-Nissan, Daimler and Volkswagen round out the top five. Google sits in sixth place with Tesla in twelfth.
Beyond the safety benefits of selfdriving vehicles, the automotive industry is also looking at these vehicles to help meet the new tough U.S CAFE (Corporate Average Fuel Economy) standards. Self-driving vehicles do not speed or drive with a heavy foot, do not get lost and can avoid traffic delays by adjusting their course. These qualities make for a more fuel-efficient vehicle.
Another advantage of a self-driving vehicle is you can send it home after it drops you off at work. No more parking lot fees or, even worse, parking meters. Also, since it’s home, it’s available for use. It’s estimated the average family will need less vehicles when one of them is a self-driving vehicle. That means less California licenses/registration fees, not to mention fewer vehicles to insure.
In 2014, Nathaniel Fairfield, Google’s principal engineer, used Google’s prototype vehicle to provide his old friend, who is legally blind, the first driverless ride on a public road which was not accompanied by a test driver or police escort.
With self-driving vehicle technology, age or physical disabilities may no longer be a barrier to mobility. Just science. Can’t wait to get one of these in the shop. I think I’ll add a gas pedal to mine.
That’s all for now. Hope it was as fun and informative to you as it was to me.
As always, I’m looking for interesting automotive topics to write about. If you have any recommendations, suggestions or questions regarding a vehicle or the automotive industry in general, I can be reached at email@example.com, Facebook Complete Car Care or text 907-7661.
God Bless America and God Bless 93636
ASE Master Certified Technician since 1988
ASE L1, Advanced Level Specialists since 1992
Going HIGH Tech
The first training class this month was a “Lubricants and Filtration” class. This class was one of the most difficult and confusing automotive classes I have ever attended. The workbook is 112 pages. Many elements (like zinc) have to be removed from engine oil for emissions concerns. Also, engine oil is no longer just a lubricant. It’s the hydraulic fluid for camshaft actuators, multiple displacement solenoids, fuel injectors, turbos and much more. Different engine platforms have different requirements which creates the need for some many different oil blends. Using the wrong oil is NOT an option with modern engine platforms. No more “one size fits all.” American oils may not be compatible with European vehicles no matter what the label on the bottle says. At present, I stock 18 different types and weights of engine oil and 16 different types of transmission fluid. I have 24 feet of shelf space dedicated to engine oil filters, but that’s no longer enough.
The second class was a “Modern Air/Fuel Management” class (fuel mileage/emissions). All automotive classes are driven by emissions regulation.
With this article, I would like to discuss some exciting new technology developed in England that greatly improves automotive diagnostic capabilities. With the Pico Pressure Transducer, we can now measure internal engine pressures or, even more importantly, changes in those pressures. I know these articles can be more technical then most of you want, but they are intended to help you ask your technician the correct questions and judge his/her answers.
Last week a new customer was referred to the shop with a very poor running 2012, 2.4L, GMC Terrain. He asked us to replace his crankshaft sensor. Of course, we recommended testing his sensor first. Since he had already paid a local dealership to diagnosis the problem he declined our recommendation. You already know replacing the crankshaft sensor had no effect on the vehicle’s running condition or I wouldn’t be writing about it.
We retrieved two codes from the Powertrain Control Module, P0016 (Crankshaft position and Camshaft position implausible) and P0365 (Camshaft Position Sensor Error). Based on these two codes we surmised the camshaft and crankshaft were out of phase. The most efficient and effective diagnostic tool available for this diagnostic is a Pico Pressure Transducer. Look up “Compression Waveform WPS500X” on YouTube. The first three images are applicable to this discussion.
The modern internal combustion engine is a four-phase engine. Phase 1: The piston travels upward. Phase 2: The piston stops, reverses its direction and travels downward. Phase 3: The piston again stops, reverses its direction and travels upward again. Phase 4: Finally, the piston stops, reverses its direction and travels downward. One complete cycle consists of four 180-degree phases equaling 720 degrees of crankshaft rotation with the piston coming to a complete stop four times.
Every time the piston rises, the pressure in the cylinder rises. The highest cylinder pressure occurs when the piston reaches its maximum upward travel. Every time the piston descends, cylinder pressure decreases. The lowest cylinder pressure occurs when the piston reaches its maximum downward travel. Since the piston and crankshaft are connected, we can know the exact position of the crankshaft based on cylinder pressure changes (180, 360, 540 and 720 degrees).
The second component of our implausibility code is the camshaft. The camshaft is responsible for opening and closing the intake and exhaust valves at exact piston positions. If the phasing of the camshaft and crankshaft are correct, the camshaft will begin to open the intake valve(s) about 10 degrees before the piston starts its downward travel. When the intake valve(s) open, cylinder pressure will instantly drop to match the negative pressure in the intake manifold. If there is no decrease in cylinder pressure at 350 degrees of crankshaft rotation, the camshaft and crankshaft are not in phase.
Same thing with the exhaust valve(s). When the exhaust valve(s) open, cylinder pressure is instantly equalized to match the pressure in the exhaust manifold. If the camshaft and crankshaft are in phase, there will be a cylinder pressure increase at 130 degrees of crankshaft rotation. If not, the camshaft(s) and crankshaft are out of phase.
The timing chain or timing belt assemblies link the camshaft(s) and crank shaft together. When the timing chain or timing belt assemblies fail, those components become out of phase. A defective timing chain was responsible for the condition of our GMC Terrain.
Earlier this week we received a compression waveform from a partner automotive repair shop. They diagnosed their vehicle with a defective valve train. After removing the cylinder heads, roller valve lifters, rocker arms, push rods and the camshaft, they found no defects. When we looked at their waveform, cylinder pressure when the exhaust valve opened was 5 pounds per square inch (psi). Cylinder pressure should be closer to 1/4 psi. The exhaust was restricted. Likely the catalytic converter failed.
Also this week, a vehicle with lots of blue smoke (oil) coming from the tailpipe came into the shop. Again, the Pico Pressure Transducer is the best diagnostic tool for the job. This time, however, the transducer is connected to the engine’s oil dipstick tube. With the dipstick removed, the tube acts like a vent for the engine crankcase. When an engine has worn pistons or piston compression rings, combustion is leaked by the rings into the crankcase creating high crankcase pressures. With our vehicle, the crankcase pressures were normal (.1 -.2 psi) during all engine loads. Pistons and piston compression rings are sealing as intended. No need to rebuild or replace this engine when a new set of valve stem seals will do the job. By the way, I strongly recommend this test when buying a used car. It is a very efficient way of discerning the internal condition of the engine.
By simply threading a Pico Pressure Transducer into any spark plug hole (easiest), we are able to measure cylinder compression, exhaust back pressure, intake manifold vacuum, camshaft/ crankshaft correlation and more. New school diagnostic using modern technology is far easier, faster and more accurate then diagnostics of the past. It’s just science.
That’s all for today. Hope this helps. If you have any comments, suggestions about future topics or questions concerning a vehicle or the automotive industry, I can be reached at firstname.lastname@example.org, Facebook or text to 559-907-7661.
God Bless America and God Bless 93636.
Warren Parr, 2013 NAPA/ASE National
Technician of the Year 2nd Runner Up
Going HIGH Tech
I want to thank all the “In Good Hands” readers for your generous support and encouraging comments. This is my 29th column, WOW, how time flies. Ladies, I’m humbled. Delightful to hear from so many. Very nice and thank you. Mrs. F, thanks for the homemade apple butter. The family enjoyed it. Finally, this month’s article includes two vehicles I thought would be interesting reading, not to mention informative and potentially useful.
First up is a 2012 Chrysler Town & Country with 91,400 miles. The customer’s complaint was the Check Engine Lamp was on with a trouble code P0306 (misfire in cylinder #6) stored in the Powertrain Control Module’s history. Using a code reader, the customer self-diagnosed his problem as a defective #6 spark plug and requested a tune up. By now, YOU ALL know that’s not what was wrong.
As part of our normal diagnostic routine, we consulted the manufacturer’s Technical Service Bulletins (TSB), warranty and recall information. We discovered Chrysler TSB 09-002-14 which states “Customers may experience a Malfunction Indicator Lamp illuminated. Upon further investigation, the Technician may find that any of the following Diagnostic Trouble Codes have been set: P0300, P0302, P0304 & P0306.” The TSB goes on to say certain 2011-2013 vehicles equipped with 3.6L Pentastar engines have been granted a 10 year or 150,000-mile warranty extension.
It appears the 3.6L Pentastar engines are suffering from low compression issues on bank two. The correct repair is to replace the cylinder head. Since our customer’s complaint matches the manufactures TSB and the vehicle matches the affected vehicles’ profile, the logical place to start our diagnostic was by testing cylinder #6 for leakage (low compression). Like most modern V6 and V8 engine platforms, the bank two cylinder head is located directly under the intake manifold. Old school diagnostic techniques require us to remove the intake manifold in order to gain access to perform cranking compression and cylinder leakage verification tests. New school diagnostic, not so much.
We started by removing the fuel pump relay so the engine would not start during testing. We then placed a high current amp probe around one of our battery cables, easiest. Using the starter motor to crank the engine over, we recorded the starter motor’s current draw. Cylinders with higher compression require higher current, more work. Cylinders with lower compression require less current, less work. The starter current draw from each individual cylinder can be compared to the starter current draw from each of the other cylinders. Guess what, cylinder #6 required 20 percent less starter current. Cylinder #6 has leakage. The manufacturer’s TSB directed us straight to the cause and new school diagnostics allowed us to verify the leaking cylinder without disassembling the engine. We directed our customer to a local m a n u f a c t u r e r ’ s dealership for his extended warranty.
TECH TIP: If you have a 2011- 2013 Dodge, Chrysler or Jeep with a 3.6L Pentastar engine parked in your driveway, please be aware of this pattern failure and the manufacturer’s extended warranty.
TECH TIP: If your vehicle (any vehicle) is less than 10 years old with less than 150,000 miles, ALWAYS, ALWAYS have your technician search for TSB’s prior to performing any major repairs. If no TSB’s are discovered, keep your repair invoice in a safe location. You may be entitled to reimbursement when at a later date the manufacturer does issue a TSB with an extended warranty. If your repair facility does not have this capability, you are not an internet user, or you just need help, give us a call and we’ll walk you through it.
The second vehicle was a 2010 Mazda5 with a hard to start complaint. Our Electrical System Analyzer displayed a “FAILED BATTERY” and “LOW CHARGING” message. I needed to determine if I had one failure or two. I isolated the components and retested. Same message. Do we have a defective battery that caused an alternator failure also; an alternator failure that caused a battery failure; or “None of the Above”? The correct answer is “None of the Above”. Our battery is defective, but our charging system is in fact functioning as it’s designed.
TECH TIP: When a vehicle’s battery test FAILS, replace the battery even though it may not be displaying symptoms. Waiting stresses the alternator from constantly charging the battery to maintain its base voltage. Alternator failure can also occur increasing repair costs.
Our low battery voltage is by design. It’s Mazda’s strategy to increase fuel efficiency by decreasing the alternator’s load on the engine. In order to properly test this vehicle’s charging system a scanner is needed. At engine idle with all electrical loads off, the Powertrain Control Module (PCM) was commanding the alternator at 25 percent duty cycle. I increased the demand/load on the electrical system by turning on the air conditioning. The PCM increased the duty cycle to compensate. High beam headlamps next. Again, the duty cycle increased. I continued to increase the electrical system load until the duty cycle was near 100 percent. The battery voltage remained constant during the entire test. The alternator was fine. A new battery was all that was need.
“Do it Yourselfers,” modern electrical system diagnostic can be tricky. Old school diagnostic and technology can mislead you.
TECH TIP: Do your homework before replacing good parts with new parts. I can get you what you need.
“In Good Hands” readers, be sure and add this article to your files. Someday your vehicle may have a FAILED electrical system test. Be informed and ask to see your technician’s diagnostic test results. If you don’t like the answers, move on. Get a second opinion. Hope this helps.
As usual, I’m looking for interesting automotive topics to write about. If you have general or specific questions, suggestions or recommendations concerning a specific vehicle or the automotive industry, I can be contacted at email@example.com, Facebook or text at 559-907-7661.
God Bless America and God Bless 93636
ASE Certified Master and Advanced Level Technician since 1988
When the rush of summer is over, automotive technicians are bombarded with new training classes. Last weekend, I attended a high-voltage battery class in Culver City for hybrid and electric vehicles. Later this month it will be “Advanced Leak Detection and Sealing Solutions” and “Advanced Engine Condition Testing.” Early December is Duramax Diesel diagnostic AGAIN.
No rest. Automotive technology marches on.
Again, I would like to express my sincere thanks and gratitude for the great support I have received from 93636. Since I just returned from a 3-day, 16- hour hybrid (HEV) and electrical vehicle (EV) class, I thought I might discuss that technology with the “In Good Hands” readers. Very interesting to say the least.
Although HEVs are gaining popularity in the U.S. and elsewhere, it’s my opinion they are just a bridge to EV vehicles. Once high-voltage battery development and technology deliver 500 miles on a single charge and EV charging stations become more prevalent, there will be no need for HEVs.
Hybrid vehicles are very complex because they integrate two different propulsion systems: A gasoline engine with high-voltage electric motors. It takes a lot of hardware and software to blend those power sources seamlessly. Sometime the HEV is powered down the road by an electric motor only. The more electric, the less gasoline is used. Most of the time, however, the vehicle is powered by a very small, under-powered gasoline engine to decrease fuel consumption. When additional power is needed, it’s supplied by the electric motor. The electric motor acts like a turbocharger, adding power proportional to the driver’s request. Hybrids range in cost from $19,000 for a Prius C to $130,000 for a Lexus LS 600hL.
Just to add a little perspective, the Saturn V rocket that powered mankind to the moon and back had six computers onboard at a weight of 72.5 pounds. The 2004 Prius High-Voltage Battery computer (one of dozens onboard) has five times that capability and weighs just a couple of pounds.
The first modern production HEV sold in America was the 2000 Honda Insight. The Toyota Prius followed the next year. The first pure EV sold in America was the 2009 Tesla Roadster. Electric Vehicles range in price from approximately $25,000 to $100,000 and receive $7,500 in tax credits.
Automotive manufacturers became very interested in HEVs and EVs in 1990 when California introduced legislation that would require 10 percent of all vehicles sold in California to be Zero Emissions Vehicles by 2003. In June of 2002, a federal district judge issued a preliminary injunction prohibiting its enforcement, a year after the Toyota Prius hit the U.S. roads.
How does an HEV work? It starts with a high-voltage DC (direct current) battery pack. A conventional, flooded lead acid battery can-not store enough energy in relation to its weight and size to be useful. My guess is a flooded lead acid battery comparable to a nickel metal hydride (NiMH) or lithium-ion (Li-ion) battery would weigh several tons. With HEV or EVs weight is EVERYTHING.
Lithium is the lightest metal and lithium-ion batteries have the highest energy storage to mass/weight ratio. Therefore, the vast majority of electrified vehicles sold in the U.S. use lithium-ion batteries. High-voltage batteries range from 144 to 330 volts, which is in the Ford Escape. In California, all high-voltage battery packs are under warranty for 150,000 miles or 10 years.
Next, we need an inverter. Inverters convert high-voltage DC from the battery pack into high-voltage AC (alternating current) to power the AC traction motor usually located inside the transmission. The traction motor through an axle shaft spins the vehicle’s drive wheels. During braking and coasting those AC traction motors are switched to AC generators. The inverter then converts the high-voltage AC to high-voltage DC to recharge the battery pack. That process is called Regenerative Braking.
Regenerative Braking is the process where the vehicle’s inertia is converted into kinetic energy, the energy of motion. With conventional hydraulic braking, the vehicle’s kinetic energy is transferred into heat from the friction generated by the brake pads rubbing against the brake rotor. That heat energy is dissipated into the air. Regenerative Braking uses the voltage generated by the traction motor/generator during coasting and braking to recharge the high-voltage battery pack. The traction motor/generator loads the drive wheels with a braking effect. The traction motor/generator stops the vehicle, NOT the hydraulic brakes except for the last 7 mph.
Also, the voltage output of the motor/generator is proportional to the braking. The harder the brake pedal is depressed the more voltage produced. Less braking produces less voltage. The regenerative braking process is controlled by a computer that interprets various inputs to determine how much braking is safe and how much braking is requested from the driver.
Toyota Prius and many Ford HEVs have a second motor/generator in the front of the transmission. It’s driven by the gasoline engine. It recharges the HV battery pack at idle, supplies power to the traction motor and starts the gasoline engine. Not enough room in this article to sort all that out also. It’s just math and science but electric vehicles simplify things. There is no gasoline engine and no second motor generator.
Currently I favor the hydrogen fuel cell concept. Hydrogen vehicles convert the chemical energy of hydrogen into mechanical energy by reacting hydrogen and oxygen in a fuel cell to run electric motors. As of 2016, there were three hydrogen-powered cars publicly available in select markets: the Toyota Mirai, the Hyundai ix35 FCEV and the Honda Clarity.
As newer Corporate Average Fuel Economy (CAFE) standards increase pressure on auto manufacturers to increase vehicle fuel mileage, EVs and HEVs may become standard fare. The processes discussed in this article are over simplified to reduce confusion. OK, that’s all for now. Hope this information is informative and useful.
Thanks Stewart for the email. I’ll investigate that Ford Fusion computer issue and see where it leads. As always, I’m looking for suggestions, ideas and interesting automotive topics to write about. I can be reached at firstname.lastname@example.org, Facebook or text 559-907-7661.
God Bless America and God Bless 93636.
Warren Parr, 2013 NAPA/ASE National
Technician of the Year, 2nd
2017 has been a very busy and exciting year for the Parr family. All 13 children and grandchildren are doing well. Max started school, Kevin joined the Marines, Lori and I celebrated our 40th wedding anniversary and for the first time in two years our family members stationed in Okinawa, Japan came home for a visit. We are truly blessed.
The Parrs would like to express our heartfelt appreciation to our 93636 family for your generous support in 2017. We wish you all a very Merry Christmas and a healthy and prosperous 2018.
I do understand that most readers of this article will not immediately rush into the garage to implement the principles and techniques discussed. My intention is to create awareness and deliver useful information in the event you may need automotive services. My hope is that you will be a discriminating buyer asking informed and probing questions. Your answers should not be ambiguous and should include test results and the specifications for the failed component. If not, don’t hesitate to get a second and third opinion if necessary. Remember, the trial and error method of diagnostic is the least efficient and most expensive method.
During last night’s DuraMax diesel class, I noticed one of the pickup trucks had bright ORANGE COVERS over some of the electrical harnesses in the engine compartment. For the past six weeks I have been so occupied with hybrid vehicles and high voltages, the first thought that flashed into my mind was this is a diesel hybrid vehicle. Hey, the first diesel hybrids are not due until next year. After a little investigation I discovered these orange covers indicate high voltage circuits for the fuel injectors. Just to review, in the automotive world black and red cables identify 12-volt direct current (DC) circuits. Blue cables, like the ones connected to your electric steering box or the fuel injectors in your Direct Injection gasoline engine, identify 36 – 60-volt AC (alternating current) and DC circuits. Better be careful with the blue cables. If you see bright ORANGE cables or covers, they indicate high voltage circuits, AC or DC. High voltage circuits require testing equipment that meets a Category III/1,000-volt rating and rubber gloves that meet Category 0 with a 1,000-volt rating. WARNING: don’t mess with the bright orange cables or components. If you get shocked, you’re going to be hurt or worse for a very long time. In the case of the DuraMax engine, the orange cables carry up to 240 volts DC to the fuel injectors. After more than 100 years of mechanical and lowvoltage diesel fuel injection, why do we now find it necessary to use lethal voltages to operate the system?
Well, I’m glad you asked. As we all know, old school diesel engines were loud, knocked a lot and their exhaust smell was objectionable. Those engines also created higher levels of NOx emissions and particulate matter. To the average U.S. buyer those vehicles were much less desirable. In addition, U.S. Corporate Average Fuel Economy (CAFE) standards are increasing and emissions level standards decreasing so light duty diesel engines manufacturers needed a solution. That solution is the piezoelectric fuel injector. They reduce engine vibration and knock, increase fuel efficiency and performance while reducing tailpipe emissions. The word “piezo” is the Greek word for pressure. The piezoelectric effect was discovered by Jacques and Pierre Curie in 1880. When quartz crystals are compressed, a voltage is produced. When voltage is applied, they extend or flex. Piezoelectric fuel injectors have approximately 500 thinly sliced crystal wafers internally stacked one on top of another. When high voltage is applied, the wafers flex essentially pushing open the injector. When the high voltage is suspended, the wafers contract and create a voltage that is captured and used to assist with the next injector opening event in the sequence. Nothing wasted here unlike an old school solenoid fuel injector. Although each individual wafer flexes very, very little, the accumulative amount opens the injector. A fuel injector is essentially a gate. When the injector is open, fuel may pass. When it’s closed, fuel may not pass.
The Robert Bosch Company pioneered piezo fuel injector technology for use in the automotive industry. According to Bosch, piezo injectors react up to five times quicker than standard solenoid injectors. This translates into more precise fuel injection events and facilitates multiple events per injection cycle. Now instead of the one large, violent, noisy fuel injection event, fuel is delivered in a series of smaller events with a maximum total of five main, pre-and post injection events. Old school solenoid injector-pulsed events last about 1/1,000 of a second. Piezo injectors react so quickly all five injector events occur in that same span of time. Can you imagine that? Five separate and distinct injection events in 1/1,000 of a second. The main injection event is the longest and the post injection event the shortest. Gradually injecting fuel, instead of dumping it all in at once, results in a less violent, more even complete burn. The gradual rise in cylinder pressure reduces noise, vibrations and emissions.
The fuel pressure inside a DuraMax fuel injector can be as high as 29,000 pounds per square inch (PSI). WARNING: this extremely high fuel pressure can be lethal. In order to overcome the fuel force acting on the injector, an even stronger force is needed to flex the wafers and open the injector. That force is electromotive force, or voltage. Boost capacitors inside the Engine Control Module (ECM) are used to step up low voltage to high voltage. The higher the voltage the stronger the reaction of the wafers. At 29,000 psi, it takes lots of voltage to flex the piezo’s wafers enough to lift open the fuel injector plunger. Hence the need for high voltage.
Piezo injector nozzles have six openings so small I cannot visually see them. At high pressure, fuel is forced through the openings creating a very fine, high velocity mist that is evenly and uniformly spread throughout the combustion chamber. The nozzle openings are arranged so the fuel mist pattern looks like an upside-down cone or funnel.
OK, we are close, but there is one more very important ingredient missing. Not only do we need the ECM to deliver high voltage, we also need it delivered at a very high frequency or hertz (cycles per second represented as Hz). We need to cycle the wafers on and off five times in 1/1,000 of a second. I expect to see a frequency in excess of 5,000 Hz. For comparison, the light bulb in your house operates/flashes at 60 Hz. To me the high frequency is the key to the efficiency of this system.
To diagnosis this system, I set my Lab Scope sampling rate to 1 million samples per division, my time base to micro seconds (1/1,000,000 per/sec.) and connected a high voltage attenuator. This allows me to capture every fuel injection event or 1,500 per minute at idle. I can build a math channel that will isolate the injection events outside normal operational ranges to help me quickly and accurately focus my diagnostic. Lab Scopes may have once been considered a luxury, now they are essential.
WOW! This stuff is way cool. Automotive engineers and manufacturers are always looking for new and innovative ways to apply science. Case in point, piezoelectric science was discovered more than 130 years ago. It’s just math and science and that’s how it should be diagnosed and repaired.
OK guys, that’s about all for now. If you have any questions concerning the automotive industry, suggestions for topics and/or questions concerning a vehicle (gas, diesel or electric), I can be reached at email@example.com, Facebook or fax 559-907-7661.
God Bless America and God Bless 93636
Warren Parr ASE Master certified