Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the...

Bulletin number

21-010-20

Component

Electrical system: software

Summary

Flash: Transmission Control Module (TCM) Updates This bulletin involves reprogramming the TCM with the latest available software. Customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the technician may find the following Diagnostic Trouble Code (DTC) has been set:P0731 - Gear Ratio Error In 1st. The customer may describe the following condition:Rough or harsh shifting during coastdown to a stop (might also be described as a 2-1 bump)(Sales Code EZH). In addition, the following software enhancements are also available:2-1 coast down improvement(Sales Code EXF). 3-2 coast down improvement(Sales Code EXF). Improvements to 5-3 downshift with pedal to improve 5-3-2 shifts(Sales Code EXF). 6-5 coast down improvement(Sales Code EXF). 2-3 upshift with less than 30% pedal(Sales Code EXF). Clutch C adaption stability (improves shift quality for new transmissions on gear shifts that use Clutch C)(Sales Code EXF). Garage shift to D improvements(Sales Code EXF). Rolling garage shift(Sales Code EXF). Implementation of End Of Line (EOL) adaption to improve shift quality on brand new transmissions. Diagnostics improvements(Sales Codes ERB, ERT and EZH). Improve shift quality on brand new transmission(Sales Code EZH). Improvement to first 1-2 shift after start(Sales Code EZH). Improvement to 1-2 shift, especially for colder operating temperatures(Sales Code EZH). 2-3 shift feel improvement especially for colder operating temperatures(Sales Code EZH). Coastdown shift improvements (6-5, 5-4, 4-3, 3-2 and 2-1)(Sales Code EZH). Coastdown shift feel refinement for double downshifts(Sales Code EZH). Kickdown improvements for the following shifts (7-6-5-4-3, 8-6-5-4, 6-3-2, 5-3-2 and 4-2)(Sales Code EZH). Improvement to 4-2-1(Sales Code EZH). Improved 7th gear upshift timing. Downhill engine braking improvements.

Owners of these vehicles have filed 194 complaints in the electrical category.