DTC B145C: Heat Pump Ecu Communication

DTC detecting condition: 

When the heat pump ECM communication is abnormal.

Trouble symptom: 

Compressor does not operate.

Wiring diagram: 

Air conditioning system Ref. to WIRING SYSTEM (CROSSTREK MODEL (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 heat pump control module 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 B145C 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 HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the A/C control panel connector and heat pump control module connector.
   3. Using a tester, check the continuity between the A/C control panel connector and heat pump control module connector.

      Connector and terminal 

      (i181) No. 21 - (i365) No. 11:

   Is there continuity?

   Yes:  Repair or replace the open circuit of harness.

   No:  Replace the heat pump control module. Ref. to AIR CONDITIONER (HEV)>CONTROL UNIT .