Flash: Transmission Shift Enhancements This bulletin involves reprogramming of the Transmission Control...

Bulletin number

21-039-14

Component

Power train

Summary

Flash: Transmission Shift Enhancements This bulletin involves reprogramming of the Transmission Control Module (TCM) with the latest available software. The following TCM calibration improvements are available for vehicles equipped with the 845RE 8 speed transmission (sales code DFL) or 8HP70 8 speed transmission (sales code DFD or DFK). 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.5.7L gas engine (sales code EZH) Improved upshift timing in eco, base, and hill modes and while using cruise. Improved 8-7, 3-2, and 2-1 downshift timing Improved shift timing at higher altitudes. Improved torque converter engagement.

Owners of these vehicles have filed 353 complaints in the transmission category.