External Controls - Vehicles With: 8HP45 8-Speed Automatic Transmission AWD (G2413249): Operation: Notes

Shifting of the Transmission Control Switch (TCS) selector to any of the 5 positions is sensed by the Transmission Control Module (TCM). Signals from the TCS are passed to the Anti-lock Brake System (ABS) control module through the High Speed (HS) Controller Area Network (CAN) underbody systems bus. Then the 'Gear Shift Arbitrator (GSA)' software, which is integrated into the ABS control software, transmits the signal to the TCM through the Flexray. The TCM then reacts according to the selected position.

The TCS is a magnetic system using Hall effect sensors to determine the position of the selector. The SPORT (S) position selection allows the TCM to operate the transmission using the semi-automatic 'Commandshift' system.

When the TCS position is confirmed, the TCM outputs appropriate information on the FlexRay systems bus to the Body Control Module/Gateway Module (BCM/GWM). The information is received by the Instrument Cluster (IC) to display the gear selection information in the message center.