Operation

OPERATION

The electronic gear selector indicator gives an indication to the vehicle operator of the transmission gear that is currently selected with the automatic transmission gear selector lever. This indicator is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received over the Controller Area Network (CAN) data bus from the Electronic Shifter Module (ESM) (also known as the Electronic Selector Lever Module/EWM).

The gear selector indicator information is displayed by the cluster multi-function indicator Liquid Crystal Display (LCD) or dot matrix display unit soldered onto the instrument cluster electronic circuit board. The multi-function indicator is completely controlled by the instrument cluster logic circuit, and that logic will only allow the gear selector indicator information to be displayed when the instrument cluster detects that the ignition switch is in the ON position. Therefore, the gear selector indicator will always be OFF when the ignition switch is in any position except ON.

The ESM continually monitors the gear selector lever, then sends the proper gear selector lever position messages to the Transmission Control Module (TCM) (also known as the Electronic Transmission Control/ETC or EGS) and to the ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN or KOMBI). The EMIC will store a Diagnostic Trouble Code (DTC) for any malfunction it detects.

For proper diagnosis of the ESM, the TCM, the EMIC, the CAN data bus or the electronic communication related to electronic gear selector indicator operation, a diagnostic scan tool is required. Refer to the appropriate diagnostic information.