Backup Lamp: Description and Operation
BACKUP LAMPSThe B/U LP 20 A fuse in the underhood fuse block supplies battery positive voltage to the normally open park neutral position (PNP) switch. When driver places the gear selector lever is in the REVERSE position, the PNP switch closes and the voltage is from the PNP switch to the body control module (BCM). The BCM supplies voltage on the backup lamp supply voltage circuit to the backup lamps and to the automatic day/night mirror. The backup lamps are grounded at G401.
For trailer wiring, a separate backup lamp circuit is connected through the underhood fuse block from the TRLR B/U 10 A fuse to the trailer wiring harness.