DTC B14A7: Variable Solenoid Valve Circuit

DTC detecting condition: 

Variable flow change solenoid valve circuit is open or shorted.

Trouble symptom: 

Refrigerant pressure cannot be changed.

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 module connector and variable flow change solenoid connector.

   Is the check result OK?

   Yes:  Go to  2.

   No:  Repair the connector.

2. CHECK DTC  .
   1. Start the engine.
   2. Set the A/C setting of the center information display as follows.
      • Temperature control: MAX COOL (driver's side, passenger's side)
      • A/C: ON
      • Airflow capacity: MAX
   3. Leave it for 30 seconds or more.
   4. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B14A7 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 again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
3. CHECK VARIABLE FLOW CHANGE SOLENOID  .
   1. Stop the engine.
   2. Disconnect the connector from the variable flow change solenoid. Ref. to AIR CONDITIONER>COMPRESSOR .
   3. Using a tester, measure the internal resistance of the variable flow change solenoid.

      Terminals 

      (Compressor solenoid side) No. 1 - No. 2:

   Is the resistance 10 - 12 Ω?

   Yes:  Go to  4.

   No:  Replace the compressor. Ref. to AIR CONDITIONER>COMPRESSOR .

4. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Disconnect the A/C control module connector. Ref. to AIR CONDITIONER>CONTROL UNIT .
   2. Using a tester, check the continuity between the A/C control module connector and the variable flow change solenoid connector and between the variable flow change solenoid connector and chassis ground.

      Connector & terminal 

      (Bt51) No. 1 - (i107) No. 36:

      (Bt51) No. 2 - Chassis ground:

   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 the terminals in the variable flow change solenoid connector and between the variable flow change solenoid connector and chassis ground.

   Connector & terminal 

   (Bt51) No. 1 - (Bt51) No. 2:

   (Bt51) No. 1 - Chassis ground:

   Is there continuity?

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

   No:  Replace the A/C control module. Ref. to AIR CONDITIONER>CONTROL UNIT .