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Inspection Procedure

WARNING: This page is about a different car, the 2008 Lexus IS F. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) 
    1. Disconnect the A/C pressure sensor connector
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-3 (+) - Body ground Engine switch on (IG) 4 75 to 5 25 V
      3. Fig 1: Identifying B7 Connector Terminals
      G05755252Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step  5

    OK: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (GROUND CIRCUIT) 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-1 (-) - Body ground Always Below 1 Ω
      2. Fig 2: Identifying B7 Connector Terminals
      G05755253Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step  6

    OK: Go to next step 

  3. INSPECT A/C PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) 
    1. Reconnect the A/C pressure sensor connector
    2. Remove the A/C amplifier with connectors still connected.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      J58-13 (PRE) - Body ground Engine switch on (IG) (A/C: OFF) 0.5 to 4.8 V

      HINT

      If the measured voltage is not within the normal range, there may be a malfunction in the A/C amplifier, A/C pressure sensor, or wire harness. It is also possible that the amount of refrigerant may not be appropriate.

      Fig 3: Identifying J58 Connector Terminals
      G05755254Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step  7

    OK: Go to next step 

  4. INSPECT A/C PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) 
    1. Measure the voltage when the following conditions are satisfied.
      VOLTAGE SPECIFICATIONS

      Item Condition
      Vehicle Doors Fully open
      Temperature Setting MAX COLD
      Blower Speed HI
      A/C Switch ON
      R/F Switch RECIRCULATION
      Interior Temperature 25 to 35°C (77 to 95°F)
      Engine Speed 2000 rpm
      NOTE:
      • If refrigerant pressure on the high pressure side becomes extremely high during the inspection (if the voltage exceeds 4.8 V), the fail-safe function stops compressor operation. Therefore, measure the voltage before the fail-safe operation.
      • It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the problem symptom 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 temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.

      1. Measure the voltage according to the value(s) in the table below

        Standard Voltage 

        STANDARD VOLTAGE SPECIFICATIONS

        Tester Connection Condition Specified Condition
        J58-13 (PRE) - Body ground Engine switch on (IG) (A/C: ON) 0.5 to 4.8 V

        Result 

        RESULT DESCRIPTION

        Result Proceed to
        OK (When troubleshooting according to DTC) A
        OK (When troubleshooting according to Problem Symptoms Table) B
        NG C
        Fig 4: Identifying J58 Connector Terminals
        G05755254Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE  (See PROBLEM SYMPTOMS TABLE  )

    C: Go to step  13

    A: REPLACE A/C AMPLIFIER  (See REMOVAL  )

  5. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - A/C PRESSURE SENSOR) 
    1. Disconnect the A/C amplifier connector
      Fig 5: Identifying J58 Connector Terminals
      G05755256Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-3 (+) - J58-26 (S5-2) Always Below 1 Ω
      J58-26 (S5-2) - Body ground Always 10 kΩ or higher
      3. Fig 6: Identifying B7 Connector Terminals
      G05755257Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE A/C AMPLIFIER  (See REMOVAL  )

  6. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - A/C PRESSURE SENSOR) 
    1. Disconnect the A/C amplifier connector.
      Fig 7: Identifying J58 Connector Terminals
      G05755258Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-1 (-) - J58-38 (SG-2) Always Below 1 Ω
      J58-38 (SG-2) - Body ground Always 10 kΩ or higher
      3. Fig 8: Identifying B7 Connector Terminals
      G05755259Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE A/C AMPLIFIER  (See REMOVAL  )

  7. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - A/C PRESSURE SENSOR) 
    1. Disconnect the A/C amplifier connector
      Fig 9: Identifying J58 Connector Terminals
      G05755260Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-2 (PR) - J58-13 (PRE) Always Below 1 Ω
      J58-13 (PRE) - Body ground Always 10 kΩ or higher
      3. Fig 10: Identifying B7 Connector Terminals
      G05755261Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. INSPECT FOR A/C SYSTEM LEAK 
    1. Install the manifold gauge set
    2. Recover the refrigerant from the A/C system using a refrigerant recovery unit
    3. Evacuate the A/C system and check that vacuum can be maintained in it

      OK: Vacuum can be maintained in the A/C system. 

      HINT

      If vacuum cannot be maintained in the A/C system, refrigerant may be leaking from it In this case, it is necessary to repair or replace the leaking part of the A/C system.

    NG: Go to step  12

    OK: Go to next step 

  9. CHARGE REFRIGERANT 
    1. Add an appropriate amount of refrigerant (See REPLACEMENT  ).
  10. RECHECK FOR DTC 
    1. Recheck for the DTC when the following conditions are satisfied
      ITEM CONDITION

      Item Condition
      Vehicle Doors Fully open
      Temperature Setting MAX COLD
      Blower Speed HI
      A/C Switch ON
      R/F Switch RECIRCULATION
      Interior Temperature 25 to 35°C (77 to 95°F)
      Engine Speed 2000 rpm
      NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be set. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be set after the A/C operates for 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 temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing In this case, perform the inspection in a warm indoor environment

      Result 

      RESULT DESCRIPTION

      Result Proceed to
      DTC B1423 is output A
      DTC B1423 is not output B
      NOTE: If the DTC was set due to an insufficient or excessive amount of refrigerant, the problem may have been solved after performing the previous step. However, the root cause of insufficient refrigerant may be refrigerant leaks. The root cause of excessive refrigerant may be adding refrigerant when the level was insufficient. Therefore, identify and repair the area where refrigerant leaks from as necessary.

    B: END 

    A: Go to next step 

  11. INSPECT A/C PRESSURE SENSOR 
    1. Disconnect the A/C pressure sensor connector
    2. Connect the three 1 5 V dry cell battery positive (+) lead to terminal 3, and a negative (-) lead to terminal 1.
    3. Connect a voltmeter positive (+) lead to terminal 2, and a negative (-) lead to terminal 1.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATIONS

      Tester Connection Condition Specified Condition
      B7-2 (PR) - B7-1 (-) Refrigerant pressure: 0.39 to 3.187 MPa (57 to 463 psi) 1.0 to 4.8 V
      5. Fig 11: Identifying A/C Pressure Sensor
      G05755262Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE A/C PRESSURE SENSOR  (See AIR CONDITIONING UNIT  )

    OK: REPLACE A/C AMPLIFIER  (See REMOVAL  )

  12. REPAIR A/C SYSTEM LEAK 
    1. Identify the area where refrigerant leaks from (See REFRIGERANT LINE  )
    2. Repair the identified area of the A/C system
    3. Evacuate the A/C system.

    NEXT: CHARGE REFRIGERANT  (See REPLACEMENT  )

  13. INSPECT COOLING FAN SYSTEM 
    1. Check if that the cooling fan operates normally

      HINT.

    NG: REPAIR COOLING FAN SYSTEM 

    OK: Go to next step 

  14. CHARGE REFRIGERANT 
    1. Use a refrigerant recovery unit to recover refrigerant.
    2. Evacuate the A/C system.
    3. Add an appropriate amount of refrigerant (See REPLACEMENT  ).

      HINT:

      If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system will freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant and properly evacuate the system. Add an appropriate amount of refrigerant, and check for the DTC.

  15. RECHECK FOR DTC 
    1. Recheck for the DTC when the following conditions are satisfied
      ITEM CONDITION

      Item Condition
      Vehicle Doors Fully open
      Temperature Setting MAX COLD
      Blower Speed HI
      A/C Switch ON
      R/F Switch RECIRCULATION
      Interior Temperature 25 to 35°C (77 to 95°F)
      Engine Speed 2000 rpm
      NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be set. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be set after the Air Conditioning operates for 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 temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
      • If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system will freeze in the expansion valve, blocking the flow on the high pressure side. Therefore, in order to confirm the problem, recover the refrigerant and properly evacuate the system Add an appropriate amount of refrigerant, and check for the DTC. If the DTC is not output after this work, it indicates that the cooler dryer in the condenser is not able to absorb moisture in the refrigerant cycle. It is necessary to replace the cooler dryer in order to complete the repair.

      Result 

      RESULT DESCRIPTION

      Result Proceed to
      DTC B1423 is output A
      DTC B1423 is not output B

    B: REPLACE CONDENSER WITH COOLER DRYER  (See REMOVAL  )

    A: Go to next step 

  16. REPLACE EXPANSION VALVE 
    1. Replace the expansion valve with a new one (See DISASSEMBLY  ).

      HINT.

      Replace the expansion valve with a new one because the expansion valve is either stuck or clogged

  17. CHARGE REFRIGERANT 
    1. Use a refrigerant recovery unit to recover refrigerant.
    2. Evacuate the A/C system
    3. Add an appropriate amount of refrigerant (See REPLACEMENT  )

      HINT.

      If refrigerant is added and the system has not been properly evacuated (insufficient vacuum time), moisture in the air remaining in the system will freeze in the expansion valve, blocking the flow on the high pressure side Therefore, in order to confirm the problem, recover the refrigerant and properly evacuate the system Add an appropriate amount of refrigerant, and check for the DTC

  18. RECHECK FOR DTC 
    1. Recheck for the DTC when the following conditions are satisfied
      ITEM CONDITION

      Item Condition
      Vehicle Doors Fully open
      Temperature Setting MAX COLD
      Blower Speed HI
      A/C Switch ON
      R/F Switch RECIRCULATION
      Interior Temperature 25 to 35°C (77 to 95°F)
      Engine Speed 2000 rpm
      NOTE: If refrigerant pressure on the high pressure side becomes high, the DTC will be set. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be set after the Air Conditioning operates for 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 temperature sensor and the evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
      • If refrigerant pressure is not normal after replacing the expansion valve with a normal one, the condenser or pipes may be clogged due to dirt, dust or other foreign matter. In this case, clean or replace the condenser or pipes

      Result 

      RESULT DESCRIPTION

      Result Proceed to
      DTC B1423 is not output A
      DTC B1423 is output B

    B: CLEAN OR REPLACE CONDENSER OR PIPE 

    A: END 

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