Diagnosis Procedure

HEADLAMP (LO) CIRCUIT


Description

The IPDM E/R (intelligent power distribution module engine room) controls the headlamp low relay based on inputs from the BCM via the CAN communication lines. When the headlamp low relay is energized, power flows through fuses 40 and 41, located in the IPDM E/R. Power then flows to the front combination lamps to the headlamp low beam.




HEADLAMP (LO) CIRCUIT


Diagnosis Procedure

1.CHECK HEADLAMP (LO) FUSES
1. Turn the ignition switch OFF.
2. Check that the following fuses are not open.





Is the fuse open?
YES - Repair the harness and replace the fuse.
NO - GO TO 2
2.CHECK HEADLAMP (LO) OUTPUT VOLTAGE





1. Turn the ignition switch OFF.
2. Disconnect the front combination lamp connector.
3. Turn the ignition switch ON.
4. Turn the low beam headlamps ON.
5. With the low beam headlamps ON, check the voltage between the combination lamp connector and ground.





Is battery voltage present?
YES - GO TO 4
NO - GO TO 3
3.CHECK HEADLAMP (LO) CIRCUIT FOR OPEN





1. Turn the ignition switch OFF.
2. Disconnect IPDM E/R connector.
3. Check continuity between the IPDM E/R harness connector and the front combination lamp harness connector.





Does continuity exist?
YES - GO TO 4
NO - Repair the harnesses or connectors.
4.CHECK FRONT COMBINATION LAMP (LO) GROUND CIRCUIT





Check continuity between the front combination lamp harness connector terminal and ground.





Does continuity exist?
YES - Inspect the headlamp bulb.
NO - Repair the harness.