A guy i know gave me a code reader that he got from his brother. His brother sold his cavalier, but the reader works for 82-93 gm cars and trucks. However i dont have the book that goes with it, and im really not sure how to read the codes. If you are wondering It's the cheap 20$ one from walmart. I plug it in and it goes into "feild service mode" and the fans come on, and the "SES" light starts blinking, how do i know what code it's giving me, can anybody help ?

Thanks 91Z

 

You can use your "special" code reader, or get a GM OBD I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members). You'll also need to have a Diagnostic Trouble Code recorder. I use a 3¼ x 5 ruled index card and genuine cedar #2 pencil, but I suppose any note pad and writing instrument will work for a first-timer.

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area. There should be a small rectangular cover over the access hole in the lower dash trim.



Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:



WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) and it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

Once you have a note of all error codes, check this file for the decoding:

GM Error Codes.pdf.

You'll need Adobe Acrobat Reader to open/print the file. (See link below.)

 

:sillylol: That is just great, Vader.