A/T - Harsh 5-4 Downshift After Extended Drive

01 07 71

December 19, 2007

2016941





Affected Vehicles

Condition

Update Programming, TCM, Harsh Downshift After Extended Highway Driving

Customer may experience a harsh downshift in gears 5-4 when slowing to a stop after extended highway/long distance driving.

Note:
DO NOT diagnose or replace Transmission components or Transmission Control Module (TCM) before performing the update function as explained in this bulletin.

Technical Background





Internal transmission pressure decrease in C1 clutch due to accumulated air in the C1 oil circuit. Updated Transmission Control Module (TCM) software addresses:

^ Harsh 5-4 Downshift After Exended Highway Driving

Production Solution

Updated transmission control module software.

Service

Update-Programming Procedure:

Tip:

To Update-Programming using SVM, review and follow Instructions in Technical Bulletin Instance 2014603 "Software Version Management"





Update the TCM Control Module using the SVM code listed in the table above.

Once the SVM process is complete,

^ Switch ignition OFF for 30 seconds.

^ After a minimum of 30 seconds, switch ignition ON.

^ Once Update-Programming is complete, it is recommended to use 1001- Compiling Services prompt to clear faults stored in various control modules.

^ Reset readiness code.





^ Ensure Control Module Tuning Form shown has been filled out and signed by your Customer.





Warranty





Required Parts and Tools

Additional Information

All part and service references provided in this Technical Bulletin are subject to change and/or removal. Always check with your Parts Dept. and Repair Manuals for the latest information.