DTC B2909: Steering Responsive Headlight Actuator LH

DTC detecting condition: 

Either the left SRH actuator motor failure or sensor error is detected for five seconds continuously. Or the right SRH actuator initialization does not complete even when five seconds elapses after engine on.

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 (DIAGNOSTICS)>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 B2909 displayed? (Current code)

   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 B2909 displayed? (Current code)

   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 LH and RH 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 LH connector.

      Connector & terminal 

      (B78) No. 13 - (B122) No. 12:

      (B78) No. 14 - (B122) 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 & 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 & 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 OF 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 .
   • Left 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 LH. Ref. to LIGHTING SYSTEM>HEADLIGHT ASSEMBLY .