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DTC P0534-7A: Refrigerant Gas Fluid Leak or Seal Failure [12/2023 - ]: Procedure

WARNING: This page is about a different car, the 2024 Lexus TX 550h+. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK DTC 
    1. Check for DTCs.

      Body Electrical > Air Conditioner > Trouble Codes 

      HINT: 

      Check even when the DTCs detected for temporary failures.

      Result

      Result Proceed to
      No DTCs in the table below are output A
      Any of the DTCs in the table below are output B
      Relevant DTC
      P0070-11 Ambient Temperature Sensor Circuit Short to Ground
      P0070-15 Ambient Temperature Sensor Circuit Short to Battery or Open
      P0530-1C Refrigerant Pressure Sensor Circuit Voltage Out of Range
      P15B9-62 Ambient Temperature Sensor / Ambient Temperature Sensor "B" Signal Compare Failure

    Result: 

    B 

    GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2023 - ] 

    Result: 

    A 

    See step  2

  2. CHECK REFRIGERANT PRESSURE 

    Pre-procedure1

    • Install a manifold gauge set.

      HINT: 

      Refer to ON-VEHICLE INSPECTION [09/2023 - ]

    • 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)
    • 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 conditioning pressure sensor -32768 to 32767 kPa(gauge) (-32.768 to 32.767 MPaG) Actual refrigerant pressure displayed
      • Refrigerant line (gas leak etc.)
      • Air conditioning 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 A
      Data List value matches manifold gauge set value B

    Post-procedure1

    • None

    Result: 

    B 

    INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET. Refer to  ON-VEHICLE INSPECTION [09/2023 - ] 

    Result: 

    A 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PRESSURE SENSOR - POWER SOURCE) 

    Pre-procedure1

    • Disconnect the B16 air conditioning pressure sensor connector.
    • Measure the voltage according to the value(s) in the table below.
      GTY1238965Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)

      Standard Voltage

      Tester Connection Condition Specified Condition Result
      B16-3 (+) - Body ground Ignition switch ON 4.75 to 5.25 V V

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PRESSURE SENSOR - BODY GROUND) 

    Pre-procedure1

    • Disconnect the B16 air conditioning pressure sensor connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B16-1 (-) - Body ground Always Below 1 Ω Ω
      GTY1238971Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioner Pressure Sensor)

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) 

    Pre-procedure1

    • Disconnect the B16 air conditioning pressure sensor connector.
    • Disconnect the D35 air conditioning amplifier assembly connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B16-2 (PR) - D35-6 (PRE) Always Below 1 Ω Ω
      B16-2 (PR) or D35-6 (PRE) - Other terminals and body ground Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY (SENSOR SIGNAL CIRCUIT) 
    NOTE:
    • If refrigerant pressure on the high pressure side becomes extremely high, the fail-safe function stops compressor operation.
    • It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the malfunction may recur after a while.

    HINT: 

    When the outside air temperature is low (below -1.5°C (29.3°F)), the compressor stops due to operation of the ambient temp. sensor (thermistor assembly) and the evaporator temp. sensor (No. 1 cooler thermistor) to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.

    Pre-procedure1

    • Connect the D35 air conditioning amplifier assembly connector.
    • Connect the B16 air conditioning pressure sensor connector.
    • 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)
    • Measure the voltage according to the value(s) in the table below.
      GTY1240906Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Air Conditioning Amplifier Assembly)      		 - -

      Standard Voltage

      Tester Connection Condition Specified Condition
      D35-6 (PRE) - Body ground A/C Switch ON (When compressor with motor assembly running) 0.74 to 4.61 V
    • 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 conditioning pressure sensor -32768 to 32767 kPa(gauge) (-32.768 to 32.767 MPaG) Actual refrigerant pressure displayed
      • Refrigerant line (gas leak etc.)
      • Air conditioning pressure sensor circuit malfunction

      Body Electrical > Air Conditioner > Data List 

      Tester Display
      Regulator Pressure Sensor

      OK

      The voltage and value displayed in the Data List change.

      Result

      Result Proceed to
      OK A
      NG (The voltage changes but the value displayed in the Data List does not change.) B
      NG (The voltage does not change.) C

    Post-procedure1

    • None

    Result: 

    A 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [09/2023 - ] 

    Result: 

    B 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [09/2023 - ] 

    Result: 

    C 

    REPLACE AIR CONDITIONING PRESSURE SENSOR. Refer to  REMOVAL [12/2023 - ] 

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) 

    Pre-procedure1

    • Disconnect the B16 air conditioning pressure sensor connector.
    • Disconnect the D35 air conditioning amplifier assembly connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B16-1 (-) - D35-15 (SG-4) Always Below 1 Ω Ω
      B16-1 (-) or D35-15 (SG-4) - Other terminals and body ground Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [09/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  8. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING PRESSURE SENSOR - AIR CONDITIONING AMPLIFIER ASSEMBLY) 

    Pre-procedure1

    • Disconnect the B16 air conditioning pressure sensor connector.
    • Disconnect the D35 air conditioning amplifier assembly connector.
    • Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition Result
      B16-3 (+) - D35-11 (S5 -3) Always Below 1 Ω Ω
      B16-3 (+) or D35-11 (S5 -3) - Other terminals and body ground Always 10 kΩ or higher kΩ

      Result

      Proceed to
      OK
      NG

    Post-procedure1

    • None

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [09/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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