DTC B144A Rear Vent Door Actuator Circuit Stuck

DTC detecting condition:

Rear vent actuator is locked.

Trouble symptom:

Unable to control the rear vent temperature.

Wiring diagram:

Air conditioning system <Ref. to WIRING DIAGRAM , Air Conditioning System.>

Fig 1: Rear Vent Actuator Wiring Diagram - (Open Circuit)

Courtesy of SUBARU OF AMERICA, INC.

Step	Check	Yes	No
1 CHECK CONNECTOR. Check connecting condition of the A/C Control Module connector and rear vent actuator connector. Read the DTC using Subaru Select Monitor. <Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) .>	Is DTC B144A displayed?	Go to step 2 .	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. Using the Subaru Select Monitor, change the setting of «Rear Vent Dr Act Trgt Open Angle» from the A/C diagnosis and perform the system operation check. <Ref. to SYSTEM OPERATION CHECK MODE .>	Did the rear vent actuator move to the specified target opening angle?	Rear vent actuator circuit is normal.	Go to step 3 .
3 CHECK HARNESS. Turn the ignition switch to ON. Using a tester, check the voltage between terminals. Connector & terminal (i177) No. 3 (+) - (i80) No. 12 (-):	Is the voltage 4.5 - 5.0 V?	Go to step 4 .	Repair or replace the open, short circuit of the harness.
4 CHECK HARNESS (OPEN CIRCUIT). Disconnect the connector from A/C Control Module. Using a tester, check continuity between terminals. Connector & terminal (i177) No. 5 - (i80) No. 15: (i177) No. 3 - (i80) No. 12: (i177) No. 1 - (i181) No. 18: (i177) No. 7 - (i181) No. 23: (i177) No. 6 - (i181) No. 24:	Is there continuity?	Go to step 5 .	Repair or replace the open circuit of harness.
5 CHECK REAR VENT ACTUATOR. Check the rear vent actuator parts. <Ref. to INSPECTION , Rear Vent Door Actuator.>	Is the check result OK?	Replace the A/C Control Module. <Ref. to REMOVAL , Control Unit.>	Replace the rear vent actuator. <Ref. to REMOVAL , Rear Vent Door Actuator.>