Test D: The Headlamps Are On Continuously
PINPOINT TEST D: THE HEADLAMPS ARE ON CONTINUOUSLYNormal 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 HIGH BEAM position, the voltage signal is routed to ground. When the multifunction switch is placed in the FLASH-TO-PASS position, battery voltage is routed to the LCM. When the LCM detects a request for the flash-to-pass or high beam headlamps, the LCM provides voltage to the high beam headlamps.
When the LCM detects the wipers are on for a predetermined amount of time, the LCM provides voltage to the exterior lamps.
The DTCs listed below are set only when the on-demand self-test is carried out.
DTC B1449 (Wiper Park Sense Circuit Short to Ground) - sets when the LCM detects a short to ground on the wipers on input circuit.
DTC B1472 (Lamp Headlamp Input Circuit Short Ground) - sets when the LCM detects a short to ground on the headlamps on input circuit.
DTC B1570 (Lamp Headlamp High-Beam Circuit Short to Ground) - sets when the LCM detects a short to ground on the high beam request input circuit.
DTC B1696 (Autolamp On Circuit Short to Ground) - sets when the LCM detects a short to ground on the autolamps lamps on input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Headlamp switch
- Multifunction switch
- Wig-wag module
- Windshield wiper motor
- LCM
D1-D6:
D6-D10:
D10-D14:
D14-D16:
