Model Without SRH

WARNING: This page is about a different car, the 2022 Subaru WRX. However, it is still accessible from the selected car via links, so may be relevant.

Wiring diagram:

Headlight system Ref. to WIRING SYSTEM>HEADLIGHT SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CHECK HEADLIGHT ILLUMINATION .
1. Turn the ignition switch to ON.
2. Turn the lighting switch to the switch 2 (HEAD) position and switch UP (HI) position.
Does the headlight (low beam and high beam) come on?

Yes : The headlight system is normal.

No : Go to 2.
CHECK DTC .
1. Turn the ignition switch to ON.
2. Turn the lighting switch to the switch 2 (HEAD) position and switch UP (HI) position.
3. Read the DTC of [Front Relay Control Module] using the Subaru Select Monitor. Ref. to COMMON (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)
Are any DTCs displayed?

Yes : Perform the diagnosis for the displayed DTCs. Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST

No : Go to 3.
CHECK POWER SUPPLY .
Using the Subaru Select Monitor, display the following items in the [Data monitor] of [Front Relay Control Module]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR
- [BATT Voltage (Control)]
- [BATT Voltage (BACKUP)]
- [IGN Voltage]
Is the voltage 9 - 16 V?

Yes : Go to 4.

No : Check the front relay control module and replace it if defective.
- Inspection: Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE
- Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE
PERFORM ACTIVE TEST .
Using the Subaru Select Monitor, check the following items in the [Active Test] of [Front Relay Control Module]. Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>ACTIVE TEST

NOTE:
Check the items where illumination did not occur in step 1.
- [Lighting Low RH Output]
- [Lighting Low LH Output]
- [Lighting High RH Output]
- [Lighting High LH Output]
Does the light illuminate?

Yes : Go to 9.

No : Go to 5.
CHECK HEADLIGHT POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to OFF.
2. Disconnect the front relay control module connector.
3. Measure the voltage between front relay control module connector and chassis ground.
  Connector & terminal
  
  Headlight RH
  
  (B68) No. 1 (+) - Chassis ground (-):
  
  Headlight LH
  
  (B69) No. 6 (+) - Chassis ground (-):
Is the voltage 9 - 16 V?

Yes : Go to 6.

No : Check the harness of the fuse, connector and power supply circuit. If there are no problems, replace the front relay control module. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE
CHECK HARNESS .
1. Disconnect the connector of the light which did not illuminate.
2. Check the harness between the front relay control module and the headlight.
  Connector & terminal
  
  Headlight RH (low beam)
  
  (B68) No. 2 - (B121) No. 1:
  
  Headlight RH (high beam)
  
  (B69) No. 2 - (B121) No. 3:
  
  Headlight LH (low beam)
  
  (B69) No. 8 - (B122) No. 1:
  
  Headlight LH (high beam)
  
  (B69) No. 7 - (B122) No. 3:
Is harness normal?

Yes : Go to 7.

No : Repair or replace the defective part.
CHECK HEADLIGHT .
Apply battery voltage between headlight unit connector terminals.
CAUTION:
- Make sure that the high beam illuminates because the high beam shares the same lighting body with the low beam and they are alternatively lit by switching.
- When applying battery voltage, do not mix up the positive (+) side and the negative (-) side. Incorrect polarity connection may cause internal LED damage.
Connector & terminal
- If the low beam does not illuminate
  Headlight RH
  
  (B121) No. 1 (+) - (B121) No. 2 (-):
  
  Headlight LH
  
  (B122) No. 1 (+) - (B122) No. 2 (-):
- If the high beam does not illuminate
  Headlight RH
  
  (B121) No. 3 - (B121) No. 2 (-):
  
  Headlight LH
  
  (B122) No. 3 - (B122) No. 2 (-):
Does the headlight (low beam and high beam) come on at normal brightness?

Yes : Go to 8.

No : Replace the headlight assembly. Ref. to LIGHTING SYSTEM>HEADLIGHT ASSEMBLY
CHECK HARNESS .
Check the harness between the headlight connector and the chassis ground.

Connector & terminal

Headlight RH

(B121) No. 2 - Chassis ground:

Headlight LH

(B122) No. 2 - Chassis ground:

Is harness normal?

Yes : Check the front relay control module and replace it if defective.
- Inspection: Ref. to FRONT RELAY CONTROL MODULE (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE
- Replacement: Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE
No : Repair or replace the defective part.
CHECK CURRENT DATA .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, display the following items in the [Data monitor] of [Body Control]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR
  - [Lighting II Switch Input]
  - [Dimmer Hi Switch Input]
Does the display change between [OFF] ←→ [ON] when the lighting switch is moved to the switch 2 (HEAD) and switch UP (HI) positions?

Yes : Go to 10.

No : Check the combination switch or harness for open circuit.
CHECK CURRENT DATA .
1. Turn the ignition switch to ON.
2. Using the Subaru Select Monitor, display the following items in the [Data monitor] of [Front Relay Control Module]. Ref. to COMMON (DIAGNOSTICS)>DATA MONITOR
  - [Lighting Low Request]
  - [Lighting High Request]
Does the display change to [ON] when turning the lighting switch to the switch 2 (HEAD) position and switch UP (HI) position?

Yes : Replace the front relay control module. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>FRONT RELAY CONTROL MODULE

No : Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT