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LSJ Fluctuating, Unstable or Incorrect Engine Idle (Reprogram ECM)

Subject:Fluctuating, Unstable or Incorrect Engine Idle -- LSJ (Reprogram ECM)

Models:2005-2006 Chevrolet Cobalt SS Supercharged
2004-2006 Saturn ION Redline
with Ecotec™ 2.0L I-4 Engine (VIN P -- RPO LSJ)



Condition

Some customers may comment that the engine idle may fluctuate (idle roll) a hundred rpm for several seconds when the engine is started hot or cold. Further diagnostic investigation with a scan tool may not reveal the cause. No other driveability or performance concerns may be reported.

Cause

The most likely cause of this issue may be that the engine calibrations need to be updated to correct the fluctuating engine idle .

Correction

DO NOT replace the throttle body, the ECM or any other parts.

Important: 

   • Chevrolet Dealers: The ECM calibration is available to dealerships as part of TIS2000 incremental satellite update version 6.5, which was broadcast to dealers on June 12, 2006 or later. For the dealerships that use CDs, they were mailed out June, 2006 or later.
   • Saturn Retailers: Before installing the new ECM calibration, make sure the Saturn Service Stall (SSS) version is TIS 6.5 2006 or later.
   • While the ignition is OFF, apply the parking brake to disable the daytime running lights (DRLs) prior to starting reprogramming procedures
   • The technician must select the "Reprogram" option in order to reprogram the ECM.

Reprogram the ECM with the latest calibration. This calibration, or any that follow, is designed to address this fluctuating engine idle concern. Refer to Service Programming System (SPS) in SI for reprogramming procedures. As always, make sure your Tech 2® is updated with the latest software version

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J6354

Module, Powertrain Control - Engine Reprogramming with SPS

Use Published Labor Operation Time