check engine light (gas, battery, 1996, cars)

[SamNC]

My check engine light was on, but its off now. Can a diagnosis place hook it up and see what was wrong with it (if light is off now), or does it not work that way?

[M3 Mitch]

Most cars since, what, I think 1996 are all OBD-II so will definitely store a code that can be retrieved by the guys at Autozone, etc.

Earlier cars with OBD-I usually have some way that you can read the code (raw) (by this I mean the CEL will flash in a series of quick flashes with longer pauses between them, 4 quick flashes means, D'oh, 4...) and you can look up the code in a reference manual.

Almost certainly AutoZone or similar can read the code, the CEL only comes on and stays on if you have a parameter that goes "far enough" off, and/or stays out of spec.

[North Beach Person]

Originally Posted by SamNC

My check engine light was on, but its off now. Can a diagnosis place hook it up and see what was wrong with it (if light is off now), or does it not work that way?

Unless you disconnected the battery and cleared the memory it can be hooked up and the trouble code read. You probably had a loose gas cap if it stayed on through a couple driving cycles and then went off.

[maggiekate]

Originally Posted by North Beach Person

Unless you disconnected the battery and cleared the memory it can be hooked up and the trouble code read. You probably had a loose gas cap if it stayed on through a couple driving cycles and then went off.

I had the same thing happen, and it was the gas cap was not tight. My light did not go off, but the dealer kindly did reset it for me, and said that was what the code did read. They charge, but he gave a waived fee.