Headlamp (LO) Circuit

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 over the CAN communication lines. When the headlamp low relay is energized, power flows through fuses 51 and 52, located in the IPDM E/R. Power then flows to the front combination lamps to the headlamp low beam.




Component Function Check
1.CHECK HEADLAMP (LO) OPERATION
WITHOUT CONSULT-III
1. Start IPDM E/R auto active test. Diagnosis Description.
2. Check that the headlamp is turned ON.

NOTE:
HI/LO is repeated 1 second each when using the IPDM E/R auto active test.
CONSULT-III
1. Select "EXTERNAL LAMPS" of IPDM E/R active test item.
2. With operating the test items, check that the headlamp is turned ON.





Is the headlamp turned ON?
YES - Headlamp (LO) is normal.
NO - SEE Diagnosis Procedure.




Diagnosis Procedure
Regarding Wiring Diagram information, [1][2]Electrical Diagrams or [1][2]Daytime Running Lamp.
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 - Replace the fuse after repairing the affected circuit.
NO - GO TO 2
2.CHECK HEADLAMP (LO) OUTPUT VOLTAGE
CONSULT-III
1. Turn the ignition switch OFF.
2. Disconnect the front combination lamp connector.
3. Turn the ignition switch ON.
4. Select "EXTERNAL LAMPS" of IPDM E/R active test item.





5. With EXTERNAL LAMPS ON, check the voltage between the front combination lamp connector and ground.





Is the measurement value normal?
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 - Replace IPDM E/R. Service and Repair, "Removal and
Installation".
NO - Repair the harnesses or connectors.
4.CHECK FRONT COMBINATION LAMP (LO) GROUND CIRCUIT
1. Disconnect the front combination lamp connector.





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





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