DTC B2908: Steering Responsive Headlight Actuator RH

DTC detecting condition: 

Fail flag (failures shown below) of the SRH actuator is detected for 1 second or more.

• Overheating of the actuator driving IC is detected.
• Short circuit, open circuit of the motor coil is detected.
• Abnormality of the motor position sensor is detected.
• Motor lock is detected.

Trouble symptom: 

The steering responsive headlight does not operate. SRH indicator blinks.

Wiring diagram: 

Headlight beam leveler system Ref. to WIRING SYSTEM>HEADLIGHT BEAM LEVELER SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK DTC  .
   1. Turn the ignition switch to OFF.
   2. Start the engine.
   3. Using the Subaru Select Monitor, perform the clear memory of [Headlight/Foglight]. Ref. to COMMON (DIAG)>CLEAR MEMORY .
   4. Read the DTC of [Headlight/Foglight] using the Subaru Select Monitor. Ref. to Headlight/Foglight (Diagnostics)>Diagnostic Trouble Code (DTC) .

   Is DTC B2908 displayed? (Current malfunction)

   Yes  : Go to  2 .

   No  : Even if DTC is displayed, the circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
2. CHECK DTC  .

   Read the DTC of [Headlight/Foglight] using the Subaru Select Monitor. Ref. to Headlight/Foglight (Diagnostics)>Diagnostic Trouble Code (DTC) .

   Is a DTC other than DTC B2908 displayed?

   Yes  : Perform the diagnosis other than for DTC B2909 first. Ref. to HEADLIGHT/FOGLIGHT (DIAGNOSTICS)>Diagnostic Trouble Code (DTC)>LIST .

   No  : Go to  3 .

3. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the headlight assembly RH and LH connectors.
   3. Disconnect the auto headlight beam leveler control module connector.
   4. Using a tester, measure the resistance between auto headlight beam leveler control module connector and headlight assembly RH connector.

      Connector and terminal 

      (B78) No. 13 - (B121) No. 12:

      (B78) No. 14 - (B121) No. 16:

   Is the resistance less than 1 Ω?

   Yes  : Go to  4 .

   No  : Repair or replace the open circuit of harness.

4. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

   Using a tester, measure the resistance between the auto headlight beam leveler control module connector and chassis ground.

   Connector and terminal 

   (B78) No. 13 - Chassis ground:

   (B78) No. 14 - Chassis ground:

   Is the resistance 1 MΩ or more?

   Yes  : Go to  5 .

   No  : Repair or replace the short circuit of the harness.

5. CHECK HARNESS (SHORT CIRCUIT TO POWER SUPPLY)  .
   1. Turn the ignition switch to ON.
   2. Using a tester, measure the voltage between auto headlight beam leveler control module connector and chassis ground.

      Connector and terminal 

      (B78) No. 13 (+) - Chassis ground (-):

      (B78) No. 14 (+) - Chassis ground (-):

   Is the voltage less than 1 V?

   Yes  : Go to  6 .

   No  : Repair or replace the short circuit of the harness.

6. CHECK ACTIVE TEST FOR SWIVEL ACTUATOR  .
   1. Turn the ignition switch to OFF.
   2. Connect all the disconnected connectors.
   3. Start the engine.
   4. Using the Subaru Select Monitor, check the following items in the [Active Test] of [Headlight/Foglight]. Ref. to Headlight/Foglight (Diagnostics)>Active Test .
   • Right Steering Responsive Headlight

   Is the actuator current position value approximately the same as the input value of the actuator control position?

   Yes  : Replace the auto headlight beam leveler control module. Ref. to LIGHTING SYSTEM>AUTO HEADLIGHT BEAM LEVELER CONTROL MODULE .

   No  : Replace the headlight assembly RH. Ref. to LIGHTING SYSTEM>HEADLIGHT ASSEMBLY .