2004 GMC Envoy Trouble code

you have to reprogramm the ecm.here is a bulletin for this problem.Subject: Service Engine Soon Light On, P1680 (Reprogram or Replace PCM)


Models: 2004 Buick Rainier

2004 Chevrolet Trailblazer

2004 GMC Envoy

2004 Oldsmobile Bravada

with 4.2L Engine (VIN S - RPO LL8)

Some customers may comment on the Service Engine Soon Light coming on. Upon investigation, the technician may find a P1680 diagnostic trouble codeCheck the resistance of the accelerator pedal position sensors using the procedure in the appropriate Service Information for DTC P1680.

If the resistance of the accelerator pedal position sensor is within the specifications shown in the Service Information and the vehicle was built prior to the following VIN breakpoints, then reprogram the PCM with the latest calibration.

If the resistance of the accelerator pedal position sensor is within the specifications shown in the Service Information and the vehicle was built after the following VIN breakpoints, then replace the PCM. If the resistance of the accelerator pedal position sensor is outside the specifications shown in the Service Information, then continue with the diagnostics for DTC P1680.

VIN Breakpoints

• Vehicles built at Oklahoma City Assembly Plant - 46192755


• Vehicles built at Moraine Assembly Plant - 42315833


this might help.

Thanks a lot.