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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 91 (Heating / Air Conditioning System (HV) - Diagnostic Codes (2 Of 3)) >> AIR CONDITIONING SYSTEM (for HV Model) >> DTC B1474-4B: A/C Inverter Cooling/Heating Over Temperature [11/2023 - ] >> Procedure

DTC B1474-4B: A/C Inverter Cooling/Heating Over Temperature [11/2023 - ]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. PERFORM ACTIVE TEST USING GTS 
    1. Perform the Active Test according to the display on the GTS.

      Powertrain > Engine > Active Test 

      Tester Display Measurement Item Control Range Restrict Condition
      Control the Engine Cooling Fan Duty Ratio Control the cooling fan 0 to 100% Perform this test when vehicle is stopped.

      Powertrain > Engine > Active Test 

      Tester Display
      Control the Engine Cooling Fan Duty Ratio

      OK

      Electric cooling fan operates smoothly.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO COOLING FAN SYSTEM. Refer to  ON-VEHICLE INSPECTION [12/2019 - ] 

    Result: 

    OK 

    See step  2

  2. CHECK REFRIGERANT PRESSURE 

    Pre-procedure1

    1. Install a manifold gauge set.

      HINT: 

      Refer to ON-VEHICLE INSPECTION [12/2019 - ]

    2. Prepare the vehicle according to the table below.

      Measurement Condition

      Item Condition
      Doors Fully open
      A/C Switch On
      Recirculation/fresh Control Switch Recirculation
      Set Temperature MAX COLD
      Blower Speed HI
      Air Conditioning Air Inlet Temperature 25 to 35°C (77 to 95°F)

      Procedure1

    3. Read the manifold gauge pressure.

      Standard Pressure

      Item Specified Condition
      High pressure side 1370 to 1570 kPa
      14 to 16 kgf/cm2
      199 to 228 psi
      Low pressure side 150 to 250 kPa
      1.5 to 2.5 kgf/cm2
      22 to 36 psi

      Result

      Proceed to
      OK
      NG

      Post-procedure1

    4. None

    Result: 

    NG 

    CHARGE REFRIGERANT. Refer to  REPLACEMENT [12/2019 - ] 

    Result: 

    OK 

    See step  3

  3. CLEAR DTC 
    1. Clear the DTCs.

      Body Electrical > Air Conditioner > Clear DTCs 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  4

  4. CHECK FOR DTC 

    Pre-procedure1

    1. Set the vehicle condition when the DTCs are output.
      1. Set the "Inspection Mode".

        HINT: 

        Refer to INSPECTION MODE PROCEDURE [12/2019 - ]

      2. Prepare the vehicle according to the table below for 30 minutes or more.
        Item Condition
        Blower Speed HI
        A/C Switch On
        Set Temperature MAX COLD

      Procedure1

    2. Check for DTCs.

      Body Electrical > Air Conditioner > Trouble Codes 

      NOTE:

      If the engine keeps idling when the ambient temperature is high, the compressor with motor assembly may automatically stop to protect the inverter circuit, and DTC B1474-4B may be stored.

      Result

      Result Proceed to
      B1474-4B is not output A
      B1474-4B is output B

      Post-procedure1

    3. None

    Result: 

    A 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    B 

    REPLACE COMPRESSOR WITH MOTOR ASSEMBLY. Refer to  REMOVAL [11/2023 - ] 

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