Test R: The Fog Lamps Are Inoperative

PINPOINT TEST R: THE FOG LAMPS ARE INOPERATIVE

R1-R3:

R4-R6:

R6-R8:

R8-R9:

Normal Operation
The lighting control module (LCM) sends a voltage reference signal to the headlamp switch through circuit 477 (LB/BK). When the fog lamp switch is engaged, the signal is routed to ground. When a request for the fog lamps is detected (and the exterior lamps are on), the LCM provides voltage to the fog lamp relay coil through circuit 1347 (DB/WH). Ground for the fog lamp relay coil is provided through circuit 57 (BK). Voltage for the fog lamp relay is provided by the battery junction box (BJB) through circuit 1669 (OG/LG). When the fog lamp relay is energized, voltage is routed to the fog lamps through circuit 478 (TN/OG).

Possible Causes
- Fuse
- Circuit 57 (BK) open
- Circuit 477 (LB/BK) open
- Circuit 478 (TN/OG) open
- Circuit 1347 (DB/WH) open or short to ground
- Circuit 1669 (OG/LG) open
- Fog lamp relay
- Headlamp switch
- LCM