Headlamp (LO) Circuit Check
Headlamp (LO) Circuit Check
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.
Component Function Check
1. CHECK HEADLAMP (LO) OPERATION
WITHOUT SDT
1 Start IPDM E/R auto active test. Refer to [Diagnosis System (IPDM E/R): Diagnosis Description] Diagnosis System (IPDM E/R) 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.
WITH SDT
1 Select "EXTERNAL LAMPS" of IPDM E/R active test item.
2 With the test items operating, check that the headlamp is turned ON.
Is the headlamp turned ON?
YES
Headlamp (LO) is normal.
NO
Refer to "Diagnosis Procedure".
Diagnosis Procedure
Regarding Wiring Diagram information, refer to [Headlamp: Wiring Diagram] Headlamp (without DTRL) or [Daytime Light System: Wiring Diagram] [1][2]Daytime Running Lamp (with DTRL).
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
1 Turn the ignition switch OFF.
2 Disconnect the front headlamp 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 headlamp connector and ground.
Is battery voltage present?
YES
GO TO 8
NO (Except LH with DTRL)
CHECK HEADLAMP (LO) CIRCUIT FOR OPEN GO TO 3
NO (LH with DTRL)
ERROR! Unknown action!CHECK HEADLAMP (LO) CIRCUIT FOR OPEN (LH WITH DTRL) GO TO 4
3. CHECK HEADLAMP (LO) CIRCUIT FOR OPEN (EXCEPT LH WITH DTRL)
1 Turn the ignition switch OFF.
2 Disconnect IPDM E/R connector E123.
3 Check continuity between the IPDM E/R harness connector (A) and the front headlamp harness connector (B).
Does continuity exist?
YES
Replace IPDM E/R. Refer to [IPDM E/R: Removal and Installation of IPDM E/R] Service and Repair.
NO
Repair the harnesses or connectors.
4. CHECK HEADLAMP (LO) CIRCUIT FOR OPEN (LH WITH DTRL)
1 Turn the ignition switch OFF.
2 Disconnect IPDM E/R connector E123 and daytime light relay 2 connector.
3 Check continuity between the IPDM E/R harness connector and the daytime light relay 2 harness connector.
Does continuity exist?
YES
GO TO 5
NO
Repair the harnesses or connectors.
5. CHECK DAYTIME LIGHT RELAY 2 CIRCUIT (LH WITH DTRL)
1 Check continuity between the daytime light relay 2 harness connector and the front headlamp LH harness connector.
2 Check continuity between the daytime light relay 2 harness connector and ground.
Is the measurement value normal?
YES
GO TO 6
NO
Repair the harnesses or connectors.
6. CHECK DAYTIME LIGHT RELAY 2 GROUND CIRCUIT
Check continuity between daytime light relay 2 harness connector and ground.
Does continuity exist?
YES
GO TO 7.
NO
Repair the harness or connector.
7. CHECK DAYTIME LIGHT RELAY 2
Check daytime light relay 2. Refer to "Component Inspection".
Is the inspection result normal?
YES
Replace IPDM E/R. Refer to [IPDM E/R: Removal and Installation of IPDM E/R] Service and Repair.
NO
Replace daytime light relay 2.
8. CHECK FRONT HEADLAMP (LO) GROUND CIRCUIT
Check continuity between the front headlamp harness connector terminal 2 and ground.
Does continuity exist?
YES
Inspect the headlamp bulb.
NO (Except LH with DTRL)
Repair the harness.
NO (LH with DTRL)
ERROR! Unknown action!GO TO 9
9. CHECK CONTINUITY BETWEEN FRONT HEADLAMP LH (HI) AND DAYTIME LIGHT RELAY 1
1 Disconnect daytime light relay 1 connector.
2 Check continuity between front headlamp LH harness connector and daytime light relay 1 harness connector.
Does continuity exist?
YES
GO TO 10
NO
Repair the harness or connector.
10. CHECK DAYTIME LIGHT RELAY 1 GROUND CIRCUIT
Check continuity between daytime light relay 1 harness connector and ground.
Does continuity exist?
YES
GO TO 11
NO
Repair the harness or connector.
11. CHECK DAYTIME LIGHT RELAY 1
Check daytime light relay 1. Refer to [Daytime Light Relay Circuit Check] Testing and Inspection
Is the inspection result normal?
YES
Replace IPDM E/R. Refer to [IPDM E/R: Removal and Installation of IPDM E/R] Service and Repair.
NO
Replace daytime light relay 1.
Component Inspection
1. CHECK DAYTIME LIGHT RELAY 2
1 Turn ignition switch OFF.
2 Remove daytime light relay 2.
3 Check the continuity between daytime light relay 2 terminals under the following conditions.
Is the inspection result normal?
YES
Inspection End.
NO
Replace daytime light relay 2.