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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 90 (Heating / Air Conditioning System (HV) - Diagnostic Codes (1 Of 3)) >> AIR CONDITIONING SYSTEM (for HV Model) >> DTC B1423: Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure [12/2019 - 11/2023] >> Procedure

DTC B1423: Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure [12/2019 - 11/2023]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK FOR DTC 
    1. Check for DTCs.

      Body Electrical > Air Conditioner > Trouble Codes 

      Result

      Result Proceed to
      DTC B1423 is output A
      DTC B1423 and B14B8 are output B

    Result: 

    B 

    GO TO DTC B14B8. Refer to  DTC B14B8: Refrigerant Shortage [12/2019 - 11/2023] 

    Result: 

    A 

    See step  2

  2. CHECK COMPARE REFRIGERANT GAS PRESSURE VALUES SHOWN ON GTS AND MANIFOLD GAUGE SET 
    1. Install a manifold gauge set.

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

    2. Prepare the vehicle according to the table below.
      MEASUREMENT CONDITION:

      Item Condition
      Vehicle Condition Ignition switch ON (READY)
      Doors Fully closed (windows also fully closed)
      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)
    3. Compare the values displayed in the Data List and on the manifold gauge.

      Body Electrical > Air Conditioner > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Regulator Pressure Sensor Air conditioner pressure sensor Min.: -456.68 kPaG (gauge)
      Max.: 3294.37 kPaG (gauge)      		 Actual refrigerant pressure displayed
      • Refrigerant line (gas leak etc.)
      • Air conditioner pressure sensor circuit malfunction

      Body Electrical > Air Conditioner > Data List 

      Tester Display
      Regulator Pressure Sensor

      Result

      Result Proceed to
      Data List value and manifold gauge set value do not match and Data List value: 196 kPa (2.0 kgf/cm2 ) or less A
      Data List value and manifold gauge set value do not match and Data List value: 2812 kPa (28.7 kgf/cm2 ) or less B
      Data List value matches manifold gauge set value C

    Result: 

    B 

    See step  8

    Result: 

    C 

    INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET. Refer to  ON-VEHICLE INSPECTION [12/2019 - ] 

    Result: 

    A 

    See step  3

  3. READ VALUE USING GTS (REGULATOR PRESSURE SENSOR) 
    1. Read the Data List according to the display on the GTS.

      Body Electrical > Air Conditioner > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Regulator Pressure Sensor Air conditioner pressure sensor Min.: -456.68 kPaG (gauge)
      Max.: 3294.37 kPaG (gauge)      		 Actual refrigerant pressure displayed
      • Refrigerant line (gas leak etc.)
      • Air conditioner pressure sensor circuit malfunction

      Body Electrical > Air Conditioner > Data List 

      Tester Display
      Regulator Pressure Sensor

      OK

      Disconnecting the connector of the air conditioner pressure sensor causes the Data List value to change.

      Result

      Result Proceed to
      Regulator pressure sensor value changes A
      Regulator pressure sensor value does not change B

    Result: 

    B 

    See step  6

    Result: 

    A 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - POWER SOURCE) 
    1. Disconnect the A24 air conditioner pressure sensor connector.
      GTY926230Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A24-3 (+) - Body ground Ignition switch ON 4.75 to 5.25 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONER PRESSURE SENSOR. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - ] 

    Result: 

    NG 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-11 (S5-3) - A24-3 (+) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  6. CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND) 
    1. Disconnect the A24 air conditioner pressure sensor connector.
      GTY926228Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A24-2 (PR) - Body ground Ignition switch ON 3.0 to 5.25 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-6 (PRE) or A24-2 (PR) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  8. CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND) 
    1. Disconnect the A24 air conditioner pressure sensor connector.
      GTY926186Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A24-1 (-) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  14

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (AIR CONDITIONER PRESSURE SENSOR - BODY GROUND) 
    1. Disconnect the A24 air conditioner pressure sensor connector.
      GTY926228Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A24-2 (PR) - Body ground Ignition switch ON 3.0 to 5.25 V

      Result

      Result Proceed to
      5.25 V or higher A
      3.0 to 5.25 V B
      Below 3.0 V C

    Result: 

    B 

    See step  11

    Result: 

    C 

    See step  13

    Result: 

    A 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-6 (PRE) or A24-2 (PR) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  11. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (INTERNAL CIRCUIT RESISTANCE) 
    1. Disconnect the A24 air conditioner pressure sensor connector.
      GTY926185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A24-2 (PR) - A24-3 (+) Ignition switch off 180 to 220 kΩ

      HINT: 

      After turning the ignition switch off, wait at least 30 seconds before performing the measurement.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONER PRESSURE SENSOR. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - ] 

    Result: 

    NG 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-6 (PRE) or A24-2 (PR) - Other terminals and body ground Always 10 kΩ or higher
      H63-11 (S5-3) or A24-3 (+) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  13. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-6 (PRE) - A24-2 (PR) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  14. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONER PRESSURE SENSOR) 
    1. Disconnect the H63 air conditioning amplifier assembly connector.
    2. Disconnect the A24 air conditioner pressure sensor connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      H63-15 (SG-4) - A24-1 (-) Always Below 1 Ω
      H63-15 (SG-4) or A24-1 (-) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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