L76 4L70-E Chuggle, Surge, Hesitation May Be Felt with Active Fuel Management System Cylinder Deactivation Transition from V8 Mode to V4 Mode or Harsh 1-2 Upshift (Reprogram ECM and TCM)

This bulletin is being revised to remove the 4L60-E transmission and add condition information. Please discard Corporate Bulletin Number 07-06-04-013 (Section 06 -- Engine/Propulsion System).

Some customers may comment on a chuggle, surge or hesitation felt during an Active Fuel Management System (AFM) cylinder deactivation transition point or a harsh 1-2 upshift .

Before reprogramming the ECM and TCM, compare the vehicle to a like vehicle. This may be a normal condition for an Active Fuel Management System equipped vehicle and no repairs should be attempted. The vehicle you are evaluating may be a little harsh in AFM transition. A calibration update was released for the ECM and TCM to soften the feel of the AFM transition.

SPS Information

Reprogram the ECM and TCM with the latest calibrations if the above concern is encountered. Updated ECM and TCM calibrations are now available to address this concern. These calibrations, or any that follow, are designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new ECM and TCM calibrations will be available to dealerships as part of TIS2000 incremental satellite update version 4.5, for 2007 (available on 04/23/07), and on TIS DVD version 5.0/2007 or later, which will be mailed to dealers on 05/09/2007. If you cannot access the calibration, call the Techline Customer Support Center and it will be provided. As always, make sure your Tech 2® is updated with the latest software version.

For vehicles repaired under warranty, use: