21-018-14 REV. A

Flash: Transmission Shift and Diagnostic Enhancements This bulletin involves flash reprogramming of the Transmission Control Module (TCM) with new software. NOTE: Vehicles that are being updated from TCM software p/n 682235$$AN or 682354$$AN ($$ are wild cards for any number) will not require the transmission Adaptation Learn Procedure as indicated in Service Bulletin 21-013-13. However, vehicles that are being updated from any other TCM software may require the transmission Adaptation Learn Procedure. Refer to Service Bulletin 21-013-13 for detailed procedures. Failure to perform the procedures outlined in Service Bulletin 21-013-13 on vehicles that were updated from any other TCM software besides p/n 682235$$AN or 682354$$AN may result in undesirable shift quality. Diagnostic Trouble Code (DTC) robustness improvements are included in this software release. These improvements apply to the following DTC?s: ? P072F- Stuck in Gear 4 ? P076F- Gear 7 shift incorrect ratio ? P0810- Clutch position control error ? P1CC9- Unable to engage gear ? P0734- Gear 4 shift incorrect ratio ? P061B- Internal control module torque calculation performance NOTE: Diagnostic Trouble Code (DTC) robustness improvements were included in TCM software p/n 682235$$AN or 682354$$AN ($$ are wild cards for any number). Standard diagnostic trouble shooting procedures should be followed for any vehicle equipped with TCM software p/n 682235$$AN or 682354$$AN exhibiting any of the previous codes. Transmission shift improvements are included in this software release. These improvements apply to the following: ? Garage shifts (Park to Reverse or Drive). ? Coastdown shift quality. ? Shift quality. ? Throttle response and performance feel. ? Management and prevention of busy shifting. ? Lift foot/change mind shift quality.