Flash: Improved Transmission 5-3 Coast Down Shift Quality This bulletin involves flash reprogramming of...

Bulletin number

21-020-14

Component

Electrical system

Summary

Flash: Improved Transmission 5-3 Coast Down Shift Quality This bulletin involves flash reprogramming of the Transmission Control Module (TCM) with new software.Vehicles that are being updated from TCM software p/n 682411$$AA, 682235$$AN or 682354$$AN ($$ are wild cards for any number) will not require the transmission Adaptation Learn Procedure as indicated in Service Bulletin 21-013-13. However, vehicles that are being updated from any other TCM software may require the transmission Adaptation Learn Procedure. Refer to Service Bulletin 21-013-13 for detailed procedures. Failure to perform the procedures outlined in Service Bulletin 21-013-13 on vehicles that were updated from any other TCM software besides p/n 682411$$AA, 682235$$AN or 682354$$AN may result in undesirable shift quality. Customers may indicate that they experience poor shift quality during a 5-3 coast down.

Owners of these vehicles have filed 450 complaints in the electrical category.