Test U

PINPOINT TEST U: THE TRAILER LAMPS ARE INOPERATIVE - REVERSING LAMPS

Test U1-U2:

Test U3-U5:

Normal Operation
Circuit 140 (BK/PK) supplies power to the reversing lamps and the coil side of the trailer tow reversing lamp relay. When the trailer tow reversing lamp relay is energized, voltage received from circuit 1043 (DG/YE) is switched to the trailer tow connector through circuit 963 (BK/LG). Ground is supplied to the trailer tow reversing lamp relay through circuit 1205 (BK).

Possible Causes
- Circuit 140 (BK/PK) open.
- Circuit 1043 (DG/YE) open.
- Circuit 963 (BK/LG) open.
- Circuit 1205 (BK) open.
- Trailer tow reversing lamp relay.
- Trailer.