Test T: The Fog Lamps Are Inoperative

PINPOINT TEST T: THE FOG LAMPS ARE INOPERATIVE

T1-T4:

T4-T7:

T7-T9:

T10-T11:

Normal Operation
The smart junction box (SJB) sends a voltage reference signal to the headlamp switch through circuit 1406 (YE/LG). When the fog lamp switch is engaged, the signal is routed to ground. When the SJB detects a request for the fog lamps, the SJB provides voltage to the fog lamp relay coil through circuit 1347 (DB/WH) and the fog lamp on indicator through circuit 1407 (LB/OG). The fog lamp relay coil is grounded through circuit 1205 (BK).

The battery junction box (BJB) provides voltage to the fog lamp relay through circuit 477 (LB/BK). When the fog lamp relay is energized, voltage is routed to the fog lamps through circuit 1776 (TN/OG).

Possible Causes
- Fuse
- Circuit 477 (LB/BK) open
- Circuit 1205 (BK) open
- Circuit 1347 (DB/WH) open or short to ground
- Circuit 1406 (YE/LG) open
- Circuit 1407 (LB/OG) short to ground
- Circuit 1776 (TN/OG) open
- Fog lamp relay
- Headlamp switch
- SJB