Operation CHARM: Car repair manuals for everyone.

Test V: The Reversing Lamps Are On Continuously

PINPOINT TEST V: THE REVERSING LAMPS ARE ON CONTINUOUSLY

Normal Operation
The smart junction box (SJB) receives the transmission gear status from the PCM (5R55S transmission), or the transmission control module (TCM) (6R60 transmission), through the instrument cluster gateway, over the communication network. When the transmission is placed in REVERSE (R), the PCM sends a message over the communication network indicating the transmission is in reverse. The SJB then provides ground to an internal relay, which routes voltage to circuit CBP15 (BN/BU) to the reversing lamps and the rear view mirror, and through circuit CAT16 (GY/BN) to the trailer tow connector.

The PCM sets DTCs if there are any concerns with the input from the transmission range (TR) sensor.

This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Rear view mirror
- SJB


V1-V3:






V4-V5: