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

DTC detecting condition: 

• Ambient sensor to combination meter circuit is shorted.
• Data to be received from the combination meter via CAN communication do not arrive.

Trouble symptom: 

• Defective ambient temperature display
• Ambient temperature is falsely recognized as 25°C, (77F) and the compartment temperature is adjusted.
• Cold air not emitted.

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 the connecting conditions of combination meter connector and ambient sensor 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 B1433 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 AMBIENT SENSOR  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the ambient sensor. Ref. to AIR CONDITIONER (HEV)>AMBIENT SENSOR .
   3. Turn the ignition switch to ON.
   4. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

   Is DTC B1432 displayed? (Current malfunction)

   Yes  : Replace the ambient sensor. Ref. to AIR CONDITIONER (HEV)>AMBIENT SENSOR .

   No  : Go to  3.

3. CHECK HARNESS  .

   Using a tester, measure the voltage between terminals in ambient sensor connector.

   Connector & terminal 

   (B480) No. 1 (+) - (B480) No. 2 (-):

   Is the voltage 4.5 - 5.5 V?

   Yes  : 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.

   No  : Go to  4.

4. CHECK HARNESS (SHORTED BETWEEN LINES)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the combination meter.
   3. Using a tester, check the continuity between terminals in ambient sensor connector.

      Connector & terminal 

      (B480) No. 1 - (B480) No. 2:

   Is there continuity?

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

   No  : Replace the combination meter. Ref. to INSTRUMENTATION/DRIVER INFO>COMBINATION METER>REMOVAL .