21-023-15

Flash: Transmission Shift And Drivability Enhancements This bulletin involves reprogramming of the Transmission Control Module (TCM) with the latest available software. A small number of customers may experience a Malfunction Indicator Lamp (MIL) Illumination. Upon further investigation, the technician may find Diagnostic Trouble Code (DTC) P0734 - Gear 4 Shift Incorrect Ratio stored in the TCM memory.