I should know this but I don't.

My SES light is coming on....how do I determine the code to find out what the problem is?

Thanks

 

Cliff,

It's really pretty easy.

First, you'll need to acquire a GM OBD-I ECM Diagnostic Trouble Code Retrieval Tool (commonly known as a paper clip to TGO members). You'll also need your ignition key, a note pad, and writing instrument (pencil, crayon, marker, pen, whatever...)

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/hush panel area. There should be a small rectangular cover over the access hole in the lower dash trim. (Some cars may have this to the left of the steering column.)



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. Store your diagnostic tool in a safe place - some companies charge upwards of $30.00 for those things.

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.)

 

Vader, Thanks for the info and the pictures. That helped so much. I'm gonna try it out this evening. Hmm..I just thought of something...hope this doesn't sound dumb, but, how do I determine if its a code 13,14,15,...etc? Flash patterns right? If so, is there a list of various flash patterns that tells which code is which? or do I need to go out and buy a book? Thanks again.

 

ok, nevermind. I figured it out.

I learned something today. I love this site

 

What a post, LOL!!