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 an erroneous Malfunction Indicator Lamp
(MIL) Illumination. Upon further investigation, the technician may find a Diagnostic Trouble
Code (DTC) 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)
? P1DCD - TCM monitoring processor performance multiple clutches locked up.
? P1B13 - Park-By-Wire unintended out of park position.
? P0734 - Gear 4 Shift Incorrect Ratio
? 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)
? P1DCD - TCM monitoring processor performance multiple clutches locked up.
? P1B13 - Park-By-Wire unintended out of park position.
? P0734 - Gear 4 Shift Incorrect Ratio
? 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.
