Engine Controls - SES Lamp ON/DTC P1680 Set
TSB SB05-01-S003Service Engine Soon Light ON, P1680
ISSUE DATE: MARCH 2005
Affected Vehicles
2004 Ascender (US/UT) with 4.2L Engine (VIN S).
Service Information
Condition:
Some customers may comment on the Service Engine Soon Light coming on. Upon investigation, the technician may find a P1680 diagnostic trouble code.
Correction:
Reprogram and/or replace PCM.
Service Procedure
Check the resistance of the accelerator pedal position sensors using the procedure in the appropriate Service Manual for DTC P1680.
If the resistance of the accelerator pedal position sensor is within the specifications shown in the Service Manual 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 Manual 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.
Reprogram the PCM with a new service calibration released with ITCS CD version 33 or newer.
Refer to Service Programming System (SPS) in the Service Manual. As always, make sure your TECH2(R) is updated with the latest software version.
Parts Information
Warranty Claim Information
Use the labor operation shown.
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