DTC B1442: Air Mix Door Actuator Circuit Short-Circuit (Driver)

DTC detecting condition: 

Air mix door actuator potentiometer circuit is shorted.

Trouble symptom: 

Temperature on the driver's side cannot be adjusted.

Wiring diagram: 

Air conditioning system Ref. to WIRING SYSTEM>AIR CONDITIONING SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK CONNECTOR  .
   1. Turn the ignition switch to OFF.
   2. Check connecting condition of the A/C control panel connector and air mix door actuator LH connector.

   Is the check result OK?

   Yes:  Go to  2.

   No:  Repair the connector.

2. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1442 displayed? (Current code)

   Yes:  Go to  3.

   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.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
3. CHECK ACTUATOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the air mix door actuator LH. Ref. to AIR CONDITIONER>AIR MIX DOOR ACTUATOR>REMOVAL .
   3. Turn the ignition switch to ON.
   4. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1440 displayed? (Current code)

   Yes:  Replace the air mix door actuator LH. Ref. to AIR CONDITIONER>AIR MIX DOOR ACTUATOR .

   No:  Go to  4.

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

      Connector & terminal 

      (B148) No. 1 - (i130) No. 30:

      (B148) No. 3 - (i130) No. 16:

      (B148) No. 5 - (i130) No. 35:

   Is there continuity?

   Yes:  Go to  5.

   No:  Repair or replace the open circuit of harness.

5. CHECK HARNESS (SHORTED BETWEEN LINES AND SHORTED TO GROUND)  .

   Using a tester, check the continuity between terminals in air mix door actuator LH connector and between air mix door actuator LH connector and chassis ground.

   Connector & terminal 

   (B148) No. 5 - (B148) No. 1:

   (B148) No. 5 - Chassis ground:

   (B148) No. 3 - (B148) No. 5:

   (B148) No. 3 - Chassis ground:

   Is there continuity?

   Yes:  Repair or replace the short circuit of the harness.

   No:  Replace the A/C control panel. Ref. to AIR CONDITIONER>CONTROL PANEL .