DTC B14A5: Refrigerant Flow Sensor Circuit Open

DTC detecting condition: 

• The voltage of the refrigerant flow sensor signal line becomes 4.7 V or more.
• Open circuit in refrigerant flow sensor

Trouble symptom: 

A/C does not function because refrigerant flow amount cannot be measured.

Wiring diagram: 

Air conditioning system Ref. to WIRING SYSTEM (IMPREZA MODEL)>AIR CONDITIONING SYSTEM>WIRING DIAGRAM . Ref. to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR 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, refrigerant flow sensor connector and coupling 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) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B14A5 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 REFRIGERANT FLOW SENSOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the refrigerant flow sensor connector.
   3. Short No. 2 and No. 3 of the refrigerant flow sensor connector (F161).
   4. Turn the ignition switch to ON.
   5. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B14A6 displayed? (Current malfunction)

   Yes  : Replace the compressor. Ref. to AIR CONDITIONER (EXCEPT FOR HEV)>COMPRESSOR .

   No  : Go to  3.

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 terminals in refrigerant flow sensor connector.

      Connector & terminal 

      (F161) No. 1 (+) - (F161) No. 2 (-):

   Is the voltage 4.5 - 5.5 V?

   Yes  : Go to  4.

   No  : Repair or replace the open circuit of harness.

4. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the A/C control panel connector.
   3. Using a tester, check the continuity between A/C control panel connector and refrigerant flow sensor connector terminals.

      Connector & terminal 

      (F161) No. 3 - (i88) No. 26:

      (F161) No. 2 - (i88) No. 18:

      (F161) No. 1 - (i88) No. 12:

   Is there continuity?

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

   No  : Repair or replace the open circuit of harness.