The complexity of today's cars have really fueled the need for specialized equipment, vast information systems and extensive training to diagnose and properly repair electronic problems. These electronics are not just in the engine controls these days; computers control the instrument gauges, brake operations, power steering, radios, power windows, door locks and many other items that we may not realize are computer controlled. When a customer takes a car in for a performance repair, he or she is essentially asking the technician to "analyze my computer system."

Vehicles today are made up of multiple microprocessors that interlink all the systems under the hood and throughout the vehicle. Not only do today's cars contain more computer power than the Apollo spacecraft that landed on the moon but the average luxury automobile has more than 100 million lines of code, spread across all of its microcontrol units which is twice the amount of code found in a desktop operating system.

The more complex a system, the more likely it will suffer troublesome errors.

To repair a vehicle, a technician cannot simply hook a car to equipment and get a code that solves the problem. A code for say an Oxygen Sensor might be caused by a bad oxygen sensor, but it could just as easily be from a bad Air Flow sensor, or fuel pump or any other sensor or component causing a fuel mixture problem. Usually, several pieces of equipment are used to check outputs based on electrical signals. These outputs must be analyzed against the vehicle's symptoms.  Because the outputs are only clues, it can sometimes take an hour or more to diagnose the problem.

Today, diagnostics of poor running or other electronic problems usually consist of 80 percent diagnostics and 20 percent repairs, compared to 20 years ago when diagnostics was only 20 percent of the job. This 180-degree change redefined the job of "auto mechanics," who today are known as "automotive technicians" because of the skills required doing this complex job.


Save $ on Diagnostic Repairs Often when you take your automobile into the repair shop you may be on your way to work or in a hurry to get on with the day and you just want the darn car fixed, but in many cases you can save money with a little preparation.

Before you take your car into the shop for a Performance or Electrical problem or maybe a noise or any type of problem that requires diagnosis before repair, take a moment to review the symptoms. Note when they started, other things you might have noticed recently and any other work that may have been done lately, especially if the symptoms are not present 100% of the time. When you bring in the car, make sure the Service Advisor or Technician writes down all the information on the repair order so that the information is not lost or forgotten when passed to the person working on your car or truck.

When an automotive technician troubleshoots a problem, any information that leads to the culprit quicker saves diagnostic time and usually less in diagnostic fees. Man made problems are sometimes the most difficult to find, which
is why noting any recent repairs or modifications can be very important.  

Ignoring that Check Engine Light   

When the first GM cars with onboard computers and diagnostic capabilities came out in the early 80’s, they could recognize a limited amount of problems and could store less than 20 trouble codes. It’s not unusual for an average car today to recognize and set 125 codes or more just for the engine and transmission.

Then there is ABS, Air Bag, suspension and other systems that have their own codes. 

Some of these engine and transmission codes are for problems that usually won’t cause problems we notice while driving. We often hear, "that light has been on for years, I don’t worry about it anymore" or "Since this is a minor  problem can I continue driving it and not fix it right now?"

If a sensor quits working or is supplying bad information the computer will often compensate by using another sensor to calculate the information. If that sensor fails also, you may be left waiting for a tow.

Unfortunately you only have one check engine light. If you ignore the light because of a problem that doesn't seem to affect the way the car drives, something else might crop up that will cause big problems and you may not know until it's too late because the light is already on.

Some problems that the light can come on to warn you about can cause poor mileage or be a warning that you may be left by the side of the road soon. Other warnings can be about things that can cause catalytic converter, transmission or engine problems.

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Wayne's Garage
27 E 27th Eugene, Oregon 97405	333 Q St. Springfield, Oregon 97477