Shift Indicator - A/T: Description and Operation

PRNDL DISPLAY

The instrument panel cluster (IPC) displays the selected gear position as determined by the powertrain control module (PCM) or the engine control module (ECM). The PCM/ECM sends a GMLAN message to the body control module (BCM) indicating the gear position. The IPC displays the gear position based on a GMLAN message from the BCM indicating the selected gear position. Refer to Data Link Communications Description and Operation and Body Control System Description and Operation. The PRNDL display blanks if:
- The PCM/ECM detects a malfunction in the transmission range switch circuit.
- The IPC detects a loss of GMLAN communications with the BCM.