Headlamp (Lo) Circuit

HEADLAMP (LO) CIRCUIT





Description
Headlamp (LO) circuit is connected to HID control unit integrated in the headlamp. Headlamp (LO) circuit turns xenon headlamp ON.
For the details of HID control unit and the xenon headlamp, Xenon Headlamp.




Component Function Check
1.CHECK HEADLAMP (LO) OPERATION
IPDM E/R AUTO ACTIVE TEST
1. Activate IPDM E/R auto active test. Diagnosis Description.
2. Check that the headlamp is turned ON.
CONSULT-III ACTIVE TEST
1. Select "EXTERNAL LAMPS" of IPDM E/R active test item.
2. With operating the test items, check that the headlamp is turned ON.

Low : Headlamp ON
Off : Headlamp OFF

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




Diagnosis Procedure
1.CHECK HEADLAMP (LO) OUTPUT VOLTAGE
CONSULT-III ACTIVE TEST
1. Turn the ignition switch OFF.
2. Disconnect the headlamp connector.
3. Turn the ignition switch ON.
4. Select "EXTERNAL LAMPS" of IPDM E/R active test item.
5. With operating the test items, check the voltage between the IPDM E/R harness connector and the ground.





Is the measurement value normal?
YES - GO TO 2.
NO - GO TO 3.
2.CHECK HEADLAMP (LO) OPEN CIRCUIT
1. Turn the ignition switch OFF.
2. Disconnect IPDM E/R connector.
3. Check continuity between the IPDM E/R harness connector and the headlamp harness connector.





Does continuity exist?
YES - GO TO 5.
NO - Repair the harnesses or connectors.
3.CHECK HEADLAMP (LO) FUSE
1. Turn the ignition switch OFF.
2. Check that the following fuses are not fusing.





Is the fuse fusing?
YES - GO TO 4.
NO - Replace IPDM E/R.
4.CHECK HEADLAMP (LO) SHORT CIRCUIT
1. Disconnect IPDM E/R connector.
2. Check continuity between the IPDM E/R harness connector and the ground.





Does continuity exist?
YES - Repair the harnesses or connectors. And then replace the fuse.
NO - Replace the fuse. (Replace IPDM E/R if the fuse is fusing again.)
5.CHECK HEADLAMP (LO) GROUND OPEN CIRCUIT
Check continuity between the headlamp harness connector and the ground.





Does continuity exist?
YES - Perform the xenon headlamp diagnosis. Xenon Headlamp.
NO - Repair the harnesses or connectors.