SRX AWD V8-4.6L VIN A (2004)
Backup Lamp: Description and Operation
BACKUP LAMPS
The fuse block left rear supplies battery positive voltage through the REVERSE LAMP fuse to the coil and switch terminals of the reverse lamp relay.
The dash integration module (DIM) sends a power mode message to the rear integration module (RIM) indicating that the ignition is in the ON position.
When the driver places the gear selector in the REVERSE position, the powertrain control module (PCM) sends a class 2 message to the RIM. The
message indicates that the gear selector lever is in the REVERSE position. The RIM then grounds the control circuit of the reverse lamp relay. This
energizes the reverse lamp relay, closing the switch side contacts and providing battery positive voltage to the backup lamp bulbs. The backup lamps are
permanently grounded at G402. With both power and ground the backup lamp bulbs illuminate. Once the driver moves the shift lever out of the reverse
position a message is sent via class 2 by the PCM causing the RIM to remove the ground from the reverse lamp relay control circuit. This opens the
contacts in the relay turning OFF the backup lamps.
