1993 Chevy Lumina Service Engine Soon Light
chapajustin
06-25-2016, 11:56 PM
The Service Engine Soon light comes on in my 1993 Chevy Lumina. I just recently started having this problem. When it first started, it wouldn't come on in the morning driving to work but on the way home from work, it would come on about 5 to 10 minutes of driving then it would go off about 3 minutes after. This was about 2 weeks ago. Now when it comes on, when I slow down or come to a complete stop and then accelerate, it feels like its having troubles/ being slow at accelerating. But once I get up to speed, it stops and the light stays on for a while. I've checked oil, tranny, and coolant levels. All are at the proper levels. Oil is changed at 3,000 miles. Mileage is currently at 129,000. I've been told that it could be the O2 sensor but they weren't really sure. Any ideas on what it could be?
Schurkey
06-26-2016, 03:22 AM
It could be any one of fifty or sixty things, and it could be some combination of things. You can't know for sure until you connect a REAL scan tool to the diagnostic connector, and start reading out codes and data-stream information.
At that mileage, it wouldn't hurt to check the fuel pressure while you're at it.
When was the last time the engine got plugs and plug wires? Air filter? Fuel filter? Had the PCV checked?
At that mileage, it wouldn't hurt to check the fuel pressure while you're at it.
When was the last time the engine got plugs and plug wires? Air filter? Fuel filter? Had the PCV checked?
Blue Bowtie
06-26-2016, 01:26 PM
In the interim you can use a jumper in the ALDL connector to display the stored error codes. This will work on a '93.
You’ll need to acquire a GM ECM Diagnostic Trouble Code Retrieval Tool. (Most of us just call them “paper clips" but GM has to have some fancy name for them to charge more.) Cut the clip in half so that one end of it is still bent in a “U” shape. If you’re careful, you can make TWO “error code retrieval tools” from one paper clip.
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 may be a small rectangular cover over the access hole in the lower dash trim.
http://www.wwdsltd.com/files/ALDLPlug.jpg
Insert a jumper tool or the aforementioned paper clip into the 'A' and 'B' terminals on the ALDL connector:
http://www.wwdsltd.com/files/ALDL.gif
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 “Check Engine”, “CEL”, "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 (http://www.wwdsltd.com/files/GMError.pdf).
You'll need Adobe Acrobat Reader (http://www.adobe.com/products/acrobat/alternate.html) to open/print the file.
You’ll need to acquire a GM ECM Diagnostic Trouble Code Retrieval Tool. (Most of us just call them “paper clips" but GM has to have some fancy name for them to charge more.) Cut the clip in half so that one end of it is still bent in a “U” shape. If you’re careful, you can make TWO “error code retrieval tools” from one paper clip.
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 may be a small rectangular cover over the access hole in the lower dash trim.
http://www.wwdsltd.com/files/ALDLPlug.jpg
Insert a jumper tool or the aforementioned paper clip into the 'A' and 'B' terminals on the ALDL connector:
http://www.wwdsltd.com/files/ALDL.gif
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 “Check Engine”, “CEL”, "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 (http://www.wwdsltd.com/files/GMError.pdf).
You'll need Adobe Acrobat Reader (http://www.adobe.com/products/acrobat/alternate.html) to open/print the file.
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