The Check Engine Light - Basics!

Today's cars are controlled by a Powertrain Control Module (PCM), your engine's computer. To repair or modify your car's performance, you need a scantool to communicate with the PCM.

The Check Engine Light, the "Malfunction Indicator Light"or "MIL" for short, is on because your vehicle's computer self-diagnosed a fault that could cause your vehicle's emissions to increase. It doesn't necessarily mean your vehicle is polluting or has a serious problem, but it might. So the light is on to let you know something is amiss that needs your attention.

Trouble is, you don't know WHAT the trouble might be. It might be something that could lead to a break-down or cause expensive engine damage, or it might be something minor like a loose gas cap (yes, the on-board diagnostic on 1996 and newer cars can even detect a loose, missing or leaking gas cap).

There's no way to know what the problem is without talking to your vehicle's computer.

How do you do that? By plugging a diagnostic scantool into your vehicle's diagnostic connector, usually found under the dash near the steering column. These tools unlock the secrets that have turned on your Check Engine Light and tell you the nature of the problem.

Yet these tools are only the messenger. It's up to you to combine information from the tool with knowledge of how the electronic system in your engine works to make an accurate diagnosis.

Read on as I unleash more Automobile Diagnostic tips.

Cheers.

Sholly-NG