Voltage is applied at all times from the R/CMPT fuse through circuit 840 to the transaxle range switch. When the transaxle is shifted into the REVERSE position, voltage is applied through the closed contacts of the transaxle range switch to the right and left backup lamps through circuit 24. The backup lamps are grounded through circuit 350 to G402.

Voltage is applied at all times from the Backup lamp fuse to the Backup lamp relay. When the transaxle is shifted into reverse position, the transaxle sends as series of signals to the power control module (PCM). The PCM then communicates this data to the Body Control Module (BCM) through the Data Line. The BCM then applies ground signal to the Backup lamp relay. This engages the relay, causing the switch inside the relay to close, allowing voltage to the backup lamps, turning them on.