STS AWD V8-4.6L VIN A (2006)
Backup Lamp: Description and Operation
BACKUP LAMPS
The left rear fuse block supplies battery positive voltage through the REVERSE LAMP fuse to the coil and switch terminals of the reverse lamp relay.
The instrument panel module (IPM) sends a power mode message to the rear integration module (RIM) indicating that the ignition is in the RUN
position. When the driver places the gear selector in the REVERSE position, the powertrain control module (PCM) sends a message via GMLAN serial
data to the RIM. The RIM provides ground to the reverse lamp relay control circuit which energizes the reverse lamp relay coil. With the reverse lamp
relay coil energized, the relay switch contacts close and allow battery positive voltage to flow from the REVERSE LAMP fuse through the relay switch
to illuminate the backup lamps. The backup lamps are permanently grounded at G402.
