An error code is something that develops when your cars sensors begin to detect a malfunction. The sensor then sends a signal to the ECM/PCM on your car and generates a Check Engine Soon or Service Engine Soon light. The computers on our cars are fairly good devices and there are scantools that you can get to read the codes.
However, we need to know you year and trim level in order to accurately tell you what the computer is on your car (ie OBD1 or OBD2 etc)
Are you seeing any service lamps on your cluster?
FYI there is a listing of error codes in Techinfo, for any Bonneville for 87-93 or 94, after that the GM uipped the computers and it gets a bit more complex. Any AutoZone in the US will do a PCM scan free of charge. To bad we don't have that service in Canada
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