Hello Camaro forums,

Am fairly new to this site but so far I'm very much liking it.

Here's the problem, my 1991 camaro RS has been giving me a check engine light ever since i got it about a month and a half ago. So today i decided to do the paper clip trick and see whats wrong. Well it seems to keep flashing code 12 (more than three times) So I looked in the haynes manual and it said something about clearing the ECM codes by diconnected the positive ECM wire by the battery. Well i couldnt find what they were talking about so i just disconnected the positive battery wire from the terminal. But still no luck. The Service Engine Soon light is still on. Anybody know why this is happening?

Thanks

Connor

 

Code 12 is normal. Its no pulse reference from the distributer. And of course there would be none if the car is not running. But code 12 will always show. It is just not supose to trigger a light if its rumming.
So possibly if code 12 is the only code in there and the light comes on while its running there may be a short in the distributer refference to the ECM. Maybe a problem with the connector on the module. Was the brown wire unplugged to time the car and not plugged back in? Should be a single wire and round connector coming out of the big harness around the AC box under the hood.

 

Just to clarify, the check engine light only comes on when the car is on but not running, when i start the car it goes away. I will take a look at the wiring today, but wouldn't a short in the distributor mean it wouldn't run? Btw the car has been running fine with the check engine light on. Also, will disconnecting the battery clear the codes in the ECM or will they automatically clear when fixed?

Appreciate your help mike

Connor

 

The check engine light is suposed to come on with the key on engine off. If it comes on while its running then there is a fault.Sounds likeyou're all good. And the car could run with a short in the system. The brown, or actually tan wire, is a bypass wire and is unplugged to adjust timing. The computer reffence wire is purple I think. The module has a 4 wire plug that goes to the computer. It also has a two wire plug that goes to the coil. That two wire plug is basicly all you need for it to run. The computer wires are for its adjustment while running.

 

Hmm thats good i guess. But that stupid light is pretty annouying, everybody who gets in my car sees it and is like "what the fxck is is up with your car man?". Well thanks for the help Mike.

Connor

 

That light can be bright from the passenger sides view. Just tell them its your On Board Diagnostics.....Like Knight Rider has.