Test G: The Autolamps Are On Continuously

PINPOINT TEST G: THE AUTOLAMPS ARE ON CONTINUOUSLY

G1-G2:

G3-G6:

G7-G10:

G10-G12:

G12-G13:

Normal Operation
The lighting control module (LCM) sends voltage reference signals to the headlamp switch through circuits 220 (VT/OG) (autolamps position), 1400 (TN/WH) (off position), 1032 (WH/BK) (park position) and 1033 (RD/YE) (headlamp position). The headlamp switch routes the 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 a request for the autolamps is detected by the LCM, the LCM monitors the state of circuit 218 (WH/VT). The light sensor is provided ground through circuit 676 (PK/OG). When high ambient light conditions exist, the light sensor pulls the voltage signal low. When low ambient light conditions exist, the voltage signal to the light sensor is read as high by the LCM. Based on input from the light sensor, LCM determines when to supply voltage to the exterior lamps.

The LCM also sends a voltage reference signal to the windshield wiper motor through circuit 28 (BK/PK). When the wiper motor is on, the signal is routed to ground.

The DTCs listed below are set only when the on-demand self-test is carried out.

DTC B1449 - sets when the LCM detects a short to ground on the wipers on input circuit.

DTC B1472 - sets when the LCM detects a short to ground on the headlamps on input circuit.

DTC B1696 - sets when the LCM detects a short to ground on the autolamps lamps on input circuit.

Possible Causes
- Circuit 28 (BK/PK) short to ground
- Circuit 57 (BK) open
- Circuit 218 (WH/VT) open or short to voltage
- Circuit 220 (VT/OG) open or short to ground
- Circuit 676 (PK/OG) open
- Circuit 1032 (WH/BK) open
- Circuit 1033 (RD/YE) open or short to ground
- Circuit 1400 (TN/WH) open
- Light sensor
- Headlamp switch
- Windshield wiper motor
- LCM