DTC B14A6: Refrigerant Flow Sensor Circuit Short-Circuit

DTC detecting condition: 

• The voltage of the refrigerant flow sensor signal line becomes 0.3 V or less.
• Short-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 B14A6 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. Turn the ignition switch to ON.
   4. 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  : Replace the compressor. Ref. to AIR CONDITIONER (EXCEPT FOR HEV)>COMPRESSOR .

   No  : Go to  3.

3. CHECK HARNESS (SHORTED BETWEEN LINES AND SHORTED TO GROUND)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the A/C control panel connector.
   3. Using a tester, check the continuity between the terminals in refrigerant flow sensor connector and between refrigerant flow sensor connector and chassis ground.

      Connector & terminal 

      (F161) No. 2 - (F161) No. 3:

      (F161) No. 3 - Chassis ground:

   Is there continuity?

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

   No  : Replace the A/C control panel. Ref. to AIR CONDITIONER (EXCEPT FOR HEV)>CONTROL PANEL .