Flash: Transmission Diagnostic And Shift Enhancements
This bulletin involves reprogramming the Transmission Control Module (TCM) with the
latest available software.
Some customers may experience a Malfunction Indicator Lamp (MIL) illumination. Upon
further investigation, a technician may find the following Diagnostic Trouble Code (DTC)
stored in the TCM memory:
· U0404 - Invalid Data Received From Gear Shift Control Module "A".
In addition, customers may experience the following conditions:
· Bumps on 2 - 1 down-shift while braking.
· The M on the shifter and Instrument cluster may be blinking.
The following improvements are included in this update:
· **Improved 2 - 1, 3 - 2 and 6 - 5 down-shifts (6.4L only).**
· Improved 1 - 2 light throttle up-shifts.