DTC B1433: Ambient Temperature Sensor Circuit Short-Circuit (Air-Conditioner)

DTC detecting condition: 

Ambient sensor to combination meter circuit is shorted.

Trouble symptom: 

• Defective ambient temperature display.
• Ambient temperature is falsely recognized, and the compartment temperature is adjusted.

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 the connecting conditions of combination meter connector and ambient sensor connector.

   Is the check result OK?

   Yes:  Go to  2.

   No:  Repair the connector.

2. CHECK DTC  .
   1. Turn the ignition switch to ON.
   2. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1432 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.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.
3. CHECK AMBIENT SENSOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from ambient sensor. Ref. to AIR CONDITIONER>AMBIENT SENSOR .
   3. Short the connector (B104).
   4. Turn the ignition switch to ON.
   5. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1433 displayed? (Current code)

   Yes:  Replace the ambient sensor. Ref. to AIR CONDITIONER>AMBIENT SENSOR>REMOVAL .

   No:  Go to  4.

4. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Restore the temporary shorted lines made in step 3.
   3. Disconnect the connector from the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .
   4. Using a tester, check the continuity between combination meter connector and ambient sensor connector.

      Connector & terminal 

      (B104) No. 1 - (i97) No. 24:

      (B104) No. 2 - (i97) No. 23: 

   Is there continuity?

   Yes:  Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER .

   No:  Repair or replace the open circuit of harness.