Rear Reflex And Backup Lamps

BACKUP LAMP  - The backup (or reverse) lamps have a path to ground at all times through the body wire harness and is secured to a ground stud on the body sheet metal within the passenger compartment.

The TCM sends the proper electronic transmission gear selector status  messages to other electronic modules over the CAN. Whenever the ignition is in the ON position, and the BCM receives an electronic message indicating the status of the transmission gear selector is in the REVERSE position, the BCM provides a battery voltage output through a high side driver to the backup lamps on the backup lamp feed circuit.