PROM - False DTC P0121, Throttle Position Sensor
File In Section: 6E - Engine Fuel & EmissionBulletin No.: 77-65-14A
Date: May, 1998
Subject:
False DTC P0121 (Reprogram PCM)
Models:
1997 Buick Century, Skylark
1997 Chevrolet Lumina, Monte Carlo, Malibu, Venture
1997 Oldsmobile Achieva, Cutlass, Cutlass Supreme, Silhouette
1997 Pontiac Grand Am, Grand Prix, Trans Sport
with 3100/3400 V6 Engine (VINs M, E - RPOs L82, LA1)
This bulletin is being revised to add additional models and calibration numbers. Please discard Corporate Bulletin 77-65-14 (Section 6E - Engine Fuel & Emission).
Condition
Some owners may experience a MIL (Malfunction Indicator Lamp) light illuminated on the vehicle's instrument panel. Additionally, the engine's normal controlled idle speed may be slightly elevated when the MIL is illuminated.
Cause
The current DTC (Diagnostic Trouble Code) P0121 is too sensitive. The rational check that the diagnostic calibration performs has been changed. Part of those changes involve eliminating the defaulted higher idle.
Correction
Check the calibration identification number utilizing a scan tool device. Re-flash with the updated calibration if the current calibration is not one listed in this bulletin. If the vehicle already has the most recent calibration, then refer to the appropriate service repair manual to diagnose and repair for DTC P0121. Test drive the vehicle after repair to ensure that the condition has been corrected. The new calibrations are available from the GM Service Technology Group starting with CD number 6 for 1998.
Important:
Do not attempt to order the calibrations from GMSPO. The calibrations are programmed into the vehicles PCM via a Techline Tool device.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation Description Labor Time
J6355 On-Car Prom Use published
Reprogramming labor operation
Flash E Prom time