What Are Diagnostics?

            In car repair shops, “diagnostics” generally means either determining the

cause of an illuminated “Check Engine Light,” determining why your car is

performing poorly, or determining why your car failed an emissions test. A vehicle

may come in for all three conditions, and the cause of each may be the same.

Sometimes, it is easy to diagnose the root cause of these problems; more often, it is

not. Problems can be complex and may only present themselves under

certain conditions. They may be intermittent, and they may be caused by

multiple interacting systems. Also, the computer input devices, fuel system

components, and ignition & engine control system parts that are the likely

causes of your concern are expensive. Usually, when you buy one of these

parts, it is yours to keep whether it is the cause of your problem or not.

Don’t throw expensive parts at your automotive problem and hope for a fix.

Have your concern diagnosed correctly the first time. This will save you

money.

            Some lower end repair shops, parts, and tire stores offer “free

diagnostics.” Generally “free diagnostics” means that an untrained oil

changer, tire buster, or parts changer will use a generic scanner and tell you

what codes are stored in your vehicles on board computer. Occasionally,

this work. Stored codes indicate that your vehicles computer has received a

signal that is outside of the expected parameters. But the codes set can be

deceptive. On many Chevy products, for example, the code P0171 indicates

that the oxygen sensor on bank one of your engine is reporting a “lean”

condition. Does this mean that there is a restriction in the fuel system, a

problem with the fuel injectors, a problem with the ignition system, or is

the oxygen sensor defective and giving an inaccurate reading? The likely

answer is that the intake manifold gaskets are leaking, allowing air to

bypass the Mass Air Flow sensor. Further testing is required to confirm

this guess.

             Modern vehicles require highly trained and experienced technicians

armed with up to date proprietary equipment and correct testing and repair

information including factory technical service bulletins (TSBs) and repair

manuals. This means that repair shops, like Sant Automotive, that tackle

complex problems requiring diagnostics must invest heavily in terms of

personnel, equipment, training, software subscriptions, and subscriptions

to information sources. Let our expertise work for you. It will save you

money.