DTC B1458: Discharge Temperature Sensor Circuit Open

WARNING: This page is about a different variant/trim than selected.

DTC detecting condition:

When Discharge temperature sensor circuit is open.

Trouble symptom:

Compressor does not operate.

Wiring diagram:

Air conditioning system Ref. to WIRING SYSTEM (CROSSTREK MODEL (HEV))>AIR CONDITIONING SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION: Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to AIR CONDITIONERS (DIAGNOSTICS) (HEV)>GENERAL DESCRIPTION>CAUTION .

CHECK CONNECTOR .
1. Check connecting condition of the A/C control panel connector, heat pump Control Module connector and Discharge temperature 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 B1458 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.
CHECK Discharge temperature sensor .
1. Turn the ignition switch to OFF.
2. Disconnect Discharge temperature sensor. Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR .
3. Short the connector i368.
4. Turn the ignition switch to ON.
5. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .
Is DTC B1459 displayed? (Current malfunction)

Yes : Replace Discharge temperature sensor. Ref. to AIR CONDITIONER (HEV)>PIPE TEMPERATURE SENSOR .

NOTE: If it is not possible to remove Discharge temperature sensor unit, replace it together with the condenser pipe. Ref. to AIR CONDITIONER (HEV)>CONDENSER .

No : Go to 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 Discharge temperature sensor connector terminals.
  Connector & terminal
  
  (i368) No. 1 (+) - (i368) No. 2 (-):
Is the voltage 4.5 - 5.5 V?

Yes : Go to 4.

No : Repair or replace the open circuit of harness.
CHECK HARNESS (OPEN CIRCUIT) .
1. Turn the ignition switch to OFF.
2. Disconnect the heat pump Control Module connector.
3. Using a tester, check the continuity between the heat pump Control Module connector and Discharge temperature sensor connector.
  Connector & terminal
  
  (i368) No. 1 - (i365) No. 6:
  
  (i368) No. 2 - (i365) No. 34:
Is there continuity?

Yes : Replace the heat pump Control Module. Ref. to AIR CONDITIONER (HEV)>CONTROL UNIT .

No : Repair or replace the open circuit of harness.