cstem

Can the ecu throw codes without the CEL (Chk engine light) coming on? I thought the CEL came on to show that you had a code? Just curios before I tear out my carpet looking!

Kai

The check engine light only comes on when the problem happens. The ECU will remember the problem until it is reset.

Example: Your O2 sensor has a short in the wiring.
-The Check Engine light will come on when the problem occurs.
-The ECU will begin to blink the O2 sensor code.

Then you turn your car off.
-The ECU will continue to blink the O2 code.
-The check engine light will be off, until the problem happens AGAIN. Only after the problem happens again will the CEL come bac on, even though the ECU is still blinking the problem.

You disconnect the battery.
-The ECU will no longer remember the code until it happens again.

In brief, the computer remembers but the light does not.

cstem

Thanks! That's why I come to this site. Elsewhere someone would have asked if I had foglights wired up causing shorting to my cel or some crazy shit. Honda-Acura.net is sweet.