Test U: The Reversing Lamps Are Inoperative

PINPOINT TEST U: THE REVERSING LAMPS ARE INOPERATIVE

U1-U2:

U3-U4:

U4-U6:

U6-U7:

Normal Operation
Voltage is supplied from the battery junction box (BJB) fuse 33 (20A) to the switched side of the reversing lamps relay. The reversing lamps relay coil power is supplied by the transmission control module (TCM) (also called a main control valve body for Expedition and a mechatronic assembly for Navigator) through circuit CAT03 (GY/BN). The reversing lamps relay coil ground is controlled by the TCM through circuit RET24 (BN/BU). When the reversing lamps relay is energized, voltage is routed to the reversing lamps through circuit CLS10 (GN/BN).

DTC P1910 - sets when the TCM detects an open from the reversing lamps relay coil voltage supply circuit.

DTC P1911 - sets when the TCM detects a short to ground from the reversing lamps relay coil voltage supply circuit.

DTC P1912 - sets when the TCM detects a short to voltage from the reversing lamps relay coil voltage supply circuit.

Possible Causes
- Fuse
- Circuit CAT03 (GY/BN) open, short to ground or voltage
- Circuit CLS10 (GN/BN) open
- Circuit RET24 (BN/BU) open
- Reversing lamps relay
- BJB
- TCM