SES light on
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From: East Tennessee
Car: 1992 Z28 Heritage Edition
Engine: L98
Transmission: T56
Axle/Gears: 3.23:1
SES light on
First off, my car is an '87 IROC w/Lb9/auto
I have not been able to figure this one out.
I'll be driving down the interstate, all guages look fine...
After maybe 45 minutes, my SES light comes on. No signs of any trouble. Guages stay fine, engine still has power.
Any ideaS? I'm gonna pull codes.
I have not been able to figure this one out.
I'll be driving down the interstate, all guages look fine...
After maybe 45 minutes, my SES light comes on. No signs of any trouble. Guages stay fine, engine still has power.
Any ideaS? I'm gonna pull codes.
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If I'm correct in my guess, the "fix" will depend upon the variety of possible causes. However, since I'm guessing, you should diagnose the problem first. Retrieve the error code before it gets erased.
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). Form this wire into a ‘U' shape.
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 on some models, and on the left on others, depending on the make and year. There should be a small rectangular cover over the access hole in the lower dash trim, or at least was when the car was delivered.
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) - 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.
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). Form this wire into a ‘U' shape.
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 on some models, and on the left on others, depending on the make and year. There should be a small rectangular cover over the access hole in the lower dash trim, or at least was when the car was delivered.
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) - 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.
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