Gear Selector Indicator

An electronic automatic transmission gear selector indicator is standard equipment on all instrument clusters. The gear selector indicator information is displayed in the center of the multi-function indicator Liquid Crystal Display (LCD) located near the lower edge of the instrument cluster, directly below the speedometer. The gear selector indicator displays the following characters as they are selected: ""P"," "R," "N," "D," "4," "3," "2," and "1." Respectively, these characters represent the currently selected park, reverse, neutral, drive, fourth gear, third gear, second gear, and first gear positions of the transmission gear selector lever on the instrument panel.

The indications of the gear selector indicator are not visible unless the multi-function indicator LCD is illuminated and the engine is running. When illuminated, each indication appears as a dark character silhouetted against an amber field. When the exterior lighting is turned Off, the display is illuminated at maximum brightness. When the exterior lighting is turned On, the display illumination level can be adjusted in concert with the cluster general illumination lighting using the "+" (plus) and "2" (minus) multi-function indicator push buttons. The gear selector indicator is serviced as a unit with the instrument cluster.

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 from the Transmission Control Module (TCM) over the Controller Area Network (CAN) data bus. The gear selector indicator information is displayed by the multi-function indicator Liquid Crystal Display (LCD) unit on the instrument cluster electronic circuit board. The multi-function indicator LCD 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 TCM continually monitors the transmission range sensor, then sends the proper gear selector indicator position messages to the instrument cluster. For proper diagnosis of the transmission range sensor, the TCM, the CAN data bus, or the electronic message inputs to the instrument cluster that control the gear selector indicator, a DRBIII(R) scan tool is required. Refer to the appropriate diagnostic information.