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Home >> Subaru >> 2020 >> Crosstrek Base, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 25 (HVAC System (Diagnostics) (HEV)) >> Diagnostic Procedure with Diagnostic Trouble Code (DTC) >> DTC B145D: Refrigerant Pressure

DTC B145D: Refrigerant Pressure

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

DTC detecting condition: 

When the refrigerant pressure is abnormal.

Trouble symptom: 

Compressor does not operate.

Wiring diagram: 

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

G13245546Courtesy of SUBARU OF AMERICA, INC.
CAUTION:
  1. 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) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Are any DTCs displayed? (Current malfunction)

    Yes  : Perform the diagnosis for the displayed DTCs. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

    No  : Go to  2.

  2. CHECK REFRIGERANT PRESSURE  .
    1. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Air Conditioner]. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DATA MONITOR .
      • Refrigerant Pressure
    2. Attach the manifold gauge set. Ref. to AIR CONDITIONER (HEV)>REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET .
    3. Open all doors.
    4. Set the A/C control panel dials or switch and environment conditions as follows.
      • A/C switch: ON
      • FRESH/RECIRC switch: RECIRC
      • Temperature control dial: MAX COOL
      • Fan dial: MAX
      • Inlet opening temperature: 25 - 35 °C (77 - 95 °F)

    Do the [Refrigerant Pressure] value displayed on the data monitor and the manifold gauge value match?

    Yes  : Check the refrigerant pressure function. Ref. to AIR CONDITIONER (HEV)>REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET .

    No  : Go to  3.

  3. CHECK A/C CONTROL PANEL (PRESSURE SENSOR POWER SUPPLY CIRCUIT)  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the connector (B505) of the pressure sensor.
    3. Turn the ignition switch to ON.
    4. Using a tester, measure the voltage between the pressure sensor connector and chassis ground.

      Connector & terminal 

      (B505) No. 3 (+) - Chassis ground (-):

    Is the voltage 4.5 - 5.5 V?

    Yes  : Go to  4.

    No  : Go to  10.

  4. CHECK PRESSURE SENSOR (PRESSURE SENSOR GROUND CIRCUIT)  .

    Using a tester, measure the resistance between the pressure sensor connector and chassis ground.

    Connector & terminal 

    (B505) No. 1 - Chassis ground:

    Is the resistance less than 1 Ω?

    Yes  : Go to  5.

    No  : Go to  8.

  5. CHECK HARNESS (OPEN CIRCUIT)  .
    1. Disconnect the A/C control panel connector (i181).
    2. Using a tester, measure the resistance between the pressure sensor connector and A/C control panel connector.

      Connector & terminal 

      (B505) No. 2 - (i181) No. 8:

    Is the resistance less than 1 Ω?

    Yes  : Go to  6.

    No  : Repair or replace the open circuit of harness.

  6. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

    Using a tester, measure the resistance between the pressure sensor connector and chassis ground.

    Connector & terminal 

    (B505) No. 2 - Chassis ground:

    Is the resistance 10 kΩ or more?

    Yes  : Go to  7.

    No  : Repair or replace the short circuit of the harness.

  7. CHECK PRESSURE SENSOR (PRESSURE SENSOR OUTPUT CIRCUIT)  .
    CAUTION:
    • If pressure in the high-pressure side increases, failsafe is triggered and the electric compressor stops compression operation.
    • As faulty phenomenon may be reproduced after a while, check the voltage value for 10 minutes.
    1. Connect the A/C control panel connector (i181).
    2. Open all doors.
    3. Set the A/C control panel dials or switch and environment conditions as follows.
      • A/C switch: ON
      • FRESH/RECIRC switch: RECIRC
      • Temperature control dial: MAX COOL
      • Fan dial: MAX
      • Inlet opening temperature: 25 - 35 °C (77 - 95 °F)
    4. Using a tester, measure the voltage between the pressure sensor connector and chassis ground.

      Connector & terminal 

      (B505) No. 2 (+) - Chassis ground (-):

    5. Using the Subaru Select Monitor, check the following items in the [Data Monitor] of [Air Conditioner]. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DATA MONITOR .
      • Refrigerant Pressure

    Is voltage 0.5 - 4.9 V, and does voltage change according to the data monitor value? (If voltage value changes even if the data monitor value does not change, go to "Yes".)

    Yes  : Go to  12.

    No  : Replace the pressure sensor. Ref. to AIR CONDITIONER (HEV)>PRESSURE SENSOR .

  8. CHECK HARNESS (OPEN CIRCUIT)  .
    1. Disconnect the A/C control panel connector (i181).
    2. Using a tester, measure the resistance between the pressure sensor connector and A/C control panel connector.

      Connector & terminal 

      (B505) No. 1 - (i181) No. 19:

    Is the resistance less than 1 Ω?

    Yes  : Go to  9.

    No  : Repair or replace the open circuit of harness.

  9. CHECK HARNESS (GROUND SHORT CIRCUIT)  .

    Using a tester, measure the resistance between the pressure sensor connector and chassis ground.

    Connector & terminal 

    (B505) No. 1 - Chassis ground:

    Is the resistance 10 kΩ or more?

    Yes  : Go to  12.

    No  : Repair or replace the short circuit of the harness.

  10. CHECK HARNESS (OPEN CIRCUIT)  .
    1. Turn the ignition switch to OFF.
    2. Disconnect the A/C control panel connector (i181).
    3. Using a tester, measure the resistance between the pressure sensor connector and A/C control panel connector.

      Connector & terminal 

      (B505) No. 3 - (i181) No. 7:

    Is the resistance less than 1 Ω?

    Yes  : Go to  11.

    No  : Repair or replace the open circuit of harness.

  11. CHECK HARNESS (GROUND SHORT CIRCUIT)  .
    1. Disconnect the A/C control panel connector (i181).
    2. Using a tester, measure the resistance between the pressure sensor connector and A/C control panel connector, and the pressure sensor connector and chassis ground.

      Connector & terminal 

      (B505) No. 3 - Chassis ground:

    Is the resistance 10 kΩ or more?

    Yes  : Go to  12.

    No  : Repair or replace the short circuit of the harness

  12. CHECK CONTROL MODULE  .
    1. Replace the A/C control panel with a properly functioning part.
    2. Read the DTC of [Air Conditioner] using the Subaru Select Monitor. Ref. to AIR CONDITIONER (DIAGNOSTICS) (HEV)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC B145D displayed? (Current malfunction)

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

    No  : Malfunction occurred in the A/C control panel.

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