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Took my wife out to dinner tonight and on the way home the check engine light came on for approx. 15 seconds, then went off. Didn't come back on again. Any way to check what cause it?
Thanks
Only if it was a "critical" trouble code. Otherwise, no code would be stored on an 'itermitant' CEL. You can check the codes [in the usual manner] to see if there is anything there. If so, it might give you some clue as to what may have triggered it.
But, it's most likely a sensor signal that was just 'out of bounds' according to its acceptable output levels that are stored in the ECM. So it's either a spurious signal that you should not worry about; or it's a sensor that is "acting up" or providing an accurate signal that is just outside 'normal' range.
Just continue to watch it for further similar incidents. Once the CEL stays on, then a code will be thrown and retained.
Thanks 7T1vette. I have never had to check the codes on this vehicle. It is my wife's vehicle. It only has 26,000 miles on it. I kind of remember reading about how to do it somewhere but it was a long time a go. Could you refresh my memory? Thanks
I think the diagnostic port is under the ashtray in your car. The exact procedure for 'pulling' the codes is in the 1982 Chevrolet Chassis Service Manual....something like 'with the ignition ON (engine OFF), momentarily jumper terminals A and B. This grounds the diagnostic terminal (B) and starts the process. The CEL light should flash "12" with a single flash followed by a double flash. After that, any other [two digit] codes that are stored in the ECM will be displayed in the same manner. The trouble code list will translate the code numbers into the affected area of the engine; that list is included in the following website:
Harbor freight has the readers cheap.Or you can use a jumper wire and count flashes but I wouldn't worry about it. Mine does it every few months. It could be the o2 sensor reading rich for a second or the egr sticking for a split second. Most of the time you'll find no code when you check.