Flash: Transmission Shift 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.
In addition, the following TCM calibration improvements are also available for vehicles equipped with the 845RE 8 speed transmission (sales code DFL). These improvements are listed per engine application.
3.0L gas engine (sales code EHD)
? Improved upshift timing.
? Improved torque converter engagement.
? Improved shift timing during tow mode operation.
? Improved shift points during aggressive driving.
? Calibration improvement to correct bump feel during 2-1 downshift.
? Improved shift timing while in snow, base, and hill modes.
3.6L gas engine (sales code ERB)
? Improved 4-3 and 3-2 downshifts.
? Improved shift timing at higher altitudes.
? Improved shift timing while in sand mode.
? Calibration improvement for multi-gear downshift timing during passing maneuvers.
? Calibration improvement for intermittent delayed upshift.
