Test D: The Headlamps Are On Continuously

PINPOINT TEST D: THE HEADLAMPS ARE ON CONTINUOUSLY

D1-D5:

D5-D9:

D9-D12:

D12-D13:

Normal Operation
The lighting control module (LCM) sends voltage signals to the headlamp switch through circuits 220 (VT/OG), 1400 (TN/WH), 1032 (WH/BK) and 1033 (RD/YE). The headlamp switch routes a signal to ground through circuit 57 (BK) for any given headlamp switch position. If the LCM detects a fault with the headlamp switch input, the LCM defaults the exterior lamps on.

When the LCM detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the LCM provides voltage through circuits 160 (DB/WH) and 161 (DG/OG) to the LH and RH low beam headlamps, respectively.

When the LCM detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the HIGH BEAM position, the LCM provides voltage through circuits 1337 (VT/YE) and 1335 (YE/WH) to the LH and RH high beam headlamps, respectively.

The LCM sends a reference signal to the multifunction switch through circuit 12 (LG/BK). When the multifunction switch is placed in the FLASH-TO-PASS position, the voltage signal is routed to ground. When the multifunction switch is placed in the HIGH BEAM position, battery voltage is routed to the LCM. When the SJB detects a request for the flash-to-pass or high beam headlamps, the LCM provides voltage to the high beam headlamps.

Possible Causes
- Circuit 12 (LG/BK) short to ground or voltage
- Circuit 57 (BK) open
- Circuit 160 (DB/WH) short to voltage
- Circuit 161 (DG/OG) short to voltage
- Circuit 220 (VT/OG) open or short to ground
- Circuit 1032 (WH/BK) open or short to ground
- Circuit 1033 (RD/YE) open or short to ground
- Circuit 1335 (YE/WH) short to voltage
- Circuit 1337 (VT/YE) short to voltage
- Circuit 1400 (TN/WH) open
- Headlamp switch
- Multifunction switch
- LCM