Check Door Lock Actuator And Circuit

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:

Door lock control system Ref. to WIRING SYSTEM>DOOR LOCK CONTROL SYSTEM>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

CHECK HARNESS (DOOR LOCK) .
1. Turn the ignition switch to OFF.
2. Disconnect the body integrated unit and each door lock actuator connector.
3. Check the harness between body integrated unit and each door lock actuator.
  Connector & terminal
  
  Front door LH
  
  (i5) No. 6 - (Df54) No. 4:
  
  Front door RH
  
  (i5) No. 7 - (Df53) No. 4:
  
  Rear door LH
  
  (i4) No. 5 - (Dr44) No. 4:
  
  Rear door RH
  
  (i4) No. 4 - (Dr43) No. 4:
Is harness normal?

Yes : Go to 2.

No : Repair or replace the defective part.
CHECK HARNESS (DOOR UNLOCK) .
Check the harness between body integrated unit and each door lock actuator.

Connector & terminal

Front door LH

(i81) No. 6 - (Df54) No. 1:

Front door RH

(i4) No. 3 - (Df53) No. 1:

Rear door LH

(i4) No. 9 - (Dr44) No. 1:

Rear door RH

(i4) No. 3 - (Dr43) No. 1:

Is harness normal?

Yes : Go to 3.

No : Repair or replace the defective part.
CHECK HARNESS (TRUNK LID UNLOCK) .
Check the harness between the body integrated unit and trunk lid lock actuator.

Connector & terminal

(i4) No. 7 - (Td47) No. 1:

Is harness normal?

Yes : Go to 4.

No : Repair or replace the defective part.
CHECK HARNESS (TRUNK LID UNLOCK) .
Measure the resistance between the trunk lid lock actuator connector and chassis ground.

Connector & terminal

(Td47) No. 2 - Chassis ground:

Is the resistance less than 10 Ω?

Yes : Go to 5.

No : Repair or replace the defective part.
CHECK BODY INTEGRATED UNIT OUTPUT SIGNAL .
1. Connect the connector of body integrated unit.
2. Measure the voltage between terminals of the body integrated unit when operating the door lock switch to LOCK direction.
  Connector & terminal
  
  Front door LH
  
  (i5) No. 6 (+) - (i81) No. 6 (-):
  
  Front door RH
  
  (i5) No. 7 (+) - (i4) No. 3 (-):
  
  Rear door LH
  
  (i4) No. 5 (+) - (i4) No. 9 (-):
  
  Rear door RH
  
  (i4) No. 4 (+) - (i4) No. 3 (-):
Does the voltage change from less than 1 V → 9 V or more? (During lock output)

Yes : Go to 6.

No : Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT
CHECK BODY INTEGRATED UNIT OUTPUT SIGNAL .
Measure the voltage between terminals of the body integrated unit when operating the door lock switch to UNLOCK direction.

Connector & terminal

Front door LH

(i81) No. 6 (+) - (i5) No. 6 (-):

Front door RH

(i4) No. 3 (+) - (i5) No. 7 (-):

Rear door LH

(i4) No. 9 (+) - (i4) No. 5 (-):

Rear door RH

(i4) No. 3 (+) - (i4) No. 4 (-):

Does the voltage change from less than 1 V → 9 V or more? (During unlock output)

Yes : Go to 7.

No : Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT
CHECK BODY INTEGRATED UNIT OUTPUT SIGNAL .
Measure the voltage between body integrated unit and chassis ground when operating the trunk opener switch.

Connector & terminal

(i4) No. 7 (+) - Chassis ground (-):

Does the voltage change from less than 1 V → 9 V or more? (During unlock output)

Yes : Go to 8.

No : Replace the body integrated unit. Ref. to BODY CONTROL/COMMUNICATION SYSTEM>BODY INTEGRATED UNIT
CHECK DOOR LOCK ACTUATOR .
Check the door lock actuator. Ref. to SECURITY AND LOCKS>DOOR LATCH & DOOR LOCK ACTUATOR ASSEMBLY>INSPECTION

Is the door lock actuator OK?

Yes : Go to 9.

No : Replace the door latch and door lock actuator assembly. Ref. to SECURITY AND LOCKS>DOOR LATCH & DOOR LOCK ACTUATOR ASSEMBLY
CHECK TRUNK LID LOCK ACTUATOR .
Check the trunk lid lock actuator. Ref. to SECURITY AND LOCKS>TRUNK LID LATCH AND ACTUATOR ASSEMBLY>INSPECTION

Is trunk lid lock actuator normal?

Yes : Check the connection status of the harness and connector that may have a temporary poor contact.

No : Replace the trunk lid latch & actuator assembly. Ref. to SECURITY AND LOCKS>TRUNK LID LATCH AND ACTUATOR ASSEMBLY