Ok, I just bought a 02 Jimmy SLS. The engine light just came on, so I pluged in my ODB2 reader. It dosnt work. IS there a spacific reader that works, or do I need to go to GM, or is there an electrical problem thats not allowing the ODB2 reader to turn on or scan the ECU???

 

The first thing to check is the CIG fuse. If it is blown, the DLC will not get power.

 

ok, is that under the hood, or on the fuse panal at the door?

 

The CIG fuse was blown. Got a P0128 code. HEats up fine, so ill check out the coolant sensor.

 

Cool glad you found it. If your dash gauge reads properly, then it mostlikely is a problem with the ECT (engine coolant temperature) sensor which supplies the PCM with the engine temperature for use in determining the proper fuel mix.

 

Im guessing thats why its uses more fuel about 1/3 hour-hour after I clear the code.