DTC B1436: Air Mix Door Actuator Circuit Open (Passenger)

DTC detecting condition: 

Air mix door actuator potentiometer circuit is open.

Trouble symptom: 

Temperature of the passenger's side cannot be adjusted for model with left/right independent air conditioner.

Wiring diagram: 

Air conditioning system Ref. to WIRING SYSTEM (IMPREZA MODEL)>AIR CONDITIONING SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>AIR CONDITIONING SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK CONNECTOR  .
   1. Check connecting condition of the A/C control panel connector and air mix door actuator RH connector.
   2. Turn the ignition switch to ON.
   3. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1436 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 ACTUATOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the air mix door actuator RH.
   3. Short No. 2 and No. 3 of connector i175.
   4. Turn the ignition switch to ON.
   5. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1437 displayed? (Current malfunction)

   Yes:  Replace the air mix door actuator RH. Ref. to AIR CONDITIONER (EXCEPT FOR HEV)>AIR MIX DOOR ACTUATOR .

   No:  Go to  3.

3. CHECK HARNESS  .
   1. Turn the ignition switch to OFF.
   2. Restore the temporary shorted lines made in step 2.
   3. Turn the ignition switch to ON.
   4. Measure the voltage between air mix door actuator RH connector terminals using a tester.

      Connector and terminal 

      (i175) No. 1 (+) - (i175) No. 3 (-):

      Is the voltage 4.5 - 5.5 V?

      Yes:  Go to  4.

      No:  Repair or replace the open circuit of harness.

4. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the A/C control panel.
   3. Using a tester, check the continuity between A/C control panel connector and air mix door actuator RH connector terminals.

      Connector and terminal 

      (i175) No. 1 - (i88) No. 16:

      (i175) No. 2 - (i88) No. 34:

      (i175) No. 3 - (i88) No. 30:

      Is there continuity?

      Yes:  Replace the A/C control panel. Ref. to AIR CONDITIONER (EXCEPT FOR HEV)>CONTROL PANEL .

      No:  Repair or replace the open circuit of harness.