DTC B1440: Air Mix Door Actuator Circuit Open (Driver)

WARNING: This page is about a different variant/trim than selected.

DTC detecting condition:

Air mix door actuator potentiometer circuit is open.

Trouble symptom:

Temperature cannot be adjusted.

Wiring diagram:

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

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>GENERAL DESCRIPTION>CAUTION .

CHECK CONNECTOR .
1. Check connecting condition of the A/C control panel connector and air mix door actuator 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) (HEV)> DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B1440 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.
CHECK ACTUATOR .
1. Turn the ignition switch to OFF.
2. Disconnect the air mix door actuator.
3. Short No. 2 and No. 3 of i174 connector.
4. Turn the ignition switch to ON.
5. Read the DTC of [Air Conditioner] using the Subaru Select Monitor Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B1442 displayed? (Current malfunction)

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

No: Go to 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. Using a tester, measure the voltage between air mix door actuator connector terminals.
  Connector and terminal
  
  (i174) No. 1 (+) - (i174) No. 3 (-):
  
  Is the voltage 4.5 - 5.5 V?
Yes: Go to 4.

No: Repair or replace the open circuit of harness.
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 connector terminals.
  Connector and terminal
  
  (i174) No. 1 - (i181) No. 7:
  
  (i174) No. 3 - (i181) No. 19:
  
  (i174) No. 2 - (i80) No. 2:
Is there continuity?

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

No: Repair or replace the open circuit of harness.