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Home >> Toyota >> 2011 >> Highlander Hybrid >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Air Conditioning (Diagnostic Codes & Circuit Tests) (Hybrid) >> AIR CONDITIONING SYSTEM (for Manual Air Conditioning System) >> DTC B1423/23: Pressure Sensor Circuit >> Procedure

DTC B1423/23: Pressure Sensor Circuit: Procedure

  1. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) 
    1. Disconnect the A11 sensor connector.
      Fig 1: Identifying A/C Pressure Sensor Connector Terminals
      GTY188592Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Switch Condition Specified Condition
      A11-3 (+) - Body ground Ignition switch ON Approx. 5 V

    NG → See 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.
      Fig 2: Identifying Harness And Connector (Ground Circuit)
      GTY206564Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

      Tester Connection Condition Specified Condition
      A11-1 (-) - Body ground Always Below 1 Ω

    NG → See step   6 

    OK: Go to next step 

  3. CHECK AIR CONDITIONING PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) 
    1. Reconnect the A11 sensor connector.
    2. Remove the air conditioning amplifier with the connectors still connected, refer to REMOVAL .
      Fig 3: Identifying Air Conditioning Pressure Sensor (Sensor Signal Circuit)
      GTY206553Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Condition Specified Condition
      D37-9 (PRE) - Body ground Ignition switch ON
      (A/C: OFF)      		 0.76 to 4.74 V

      HINT: 

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

    NG → See step   7 

    OK: Go to next step 

  4. CHECK AIR CONDITIONING PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT) 
    1. Measure the voltage when the following conditions are satisfied.
      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)
      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.
        Fig 4: Identifying Air Conditioning Pressure Sensor (Sensor Signal Circuit)
        GTY206554Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        Standard voltage

        Tester Connection Condition Specified Condition
        D37-9 (PRE) - Body ground Conditions in chart above are met 0.76 to 4.74 V

        Result

        Result Proceed to
        OK (When troubleshooting according to DTC) A
        OK (When troubleshooting according to PROBLEM SYMPTOMS TABLE) B
        NG C

    B → See step   19 

    C → See step   13 

    A → See step   21 

  5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - AIR CONDITIONING PRESSURE SENSOR) 
    1. Disconnect the D37 amplifier connector.
      Fig 5: Identifying Air Conditioning Amplifier Connector Terminals
      GTY207467Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.
      Fig 6: Identifying A/C Pressure Sensor Connector Terminals
      GTY206566Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

      Tester Connection Condition Specified Condition
      A11-3 (+) - D37-10 (S5-3) Always Below 1 Ω
      D37-10 (S5-3) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   21 

  6. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - AIR CONDITIONING PRESSURE SENSOR) 
    1. Disconnect the D37 amplifier connector.
      Fig 7: Identifying Air Conditioning Amplifier Connector Terminals
      GTY207468Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.
      Fig 8: Identifying A/C Pressure Sensor Connector Terminals
      GTY206568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

      Tester Connection Condition Specified Condition
      A11-1 (-) - D37-13 (SG-2) Always Below 1 Ω
      D37-13 (SG-2) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   21 

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - A/C PRESSURE SENSOR) 
    1. Disconnect the D37 amplifier connector.
      Fig 9: Identifying Air Conditioning Amplifier Connector Terminals
      GTY207469Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.
      Fig 10: Identifying A/C Pressure Sensor Connector Terminals
      GTY176172Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance

      Tester Connection Condition Specified Condition
      A11-2 (PR) - D37-9 (PRE) Always Below 1 Ω
      D37-9 (PRE) - Body ground Always 10 kΩ or higher

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  8. CHECK FOR AIR CONDITIONING SYSTEM LEAK 
    1. Install a manifold gauge set.
    2. Recover the refrigerant from the air conditioning system using a refrigerant recovery unit.
    3. Evacuate the air conditioning system and check that vacuum can be maintained in it.

      OK

      Vacuum can be maintained in the air conditioning system.

      HINT: 

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

    NG → See step   12 

    OK: Go to next step 

  9. CHARGE REFRIGERANT 
    1. Add an appropriate amount of refrigerant, refer to REPLACEMENT .

    NEXT: Go to next step 

  10. CHECK DTC OUTPUT 
    1. Check for DTCs when the following conditions are satisfied.
      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)
      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 Proceed to
      DTC B1423/23 is output A
      DTC B1423/23 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 AIR CONDITIONING PRESSURE SENSOR 
    1. Install a manifold gauge set.
    2. Connect the three 1.5 V dry cell batteries' positive (+) lead to terminal 3, and the negative (-) lead to terminal 1.
      Fig 11: Identifying Air Conditioning Pressure Sensor
      GTY187002Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Connect the voltmeter's positive (+) lead to terminal 2, and the negative (-) lead to terminal 1.
    4. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Condition Specified Condition
      2 (PR) - 1 (-) Refrigerant pressure:
      0.39 to 3.187 MPa (57 to 463 psi)      		 1.0 to 4.8 V

    NG → See step   20 

    OK → See step   21 

  12. REPAIR AIR CONDITIONING SYSTEM LEAK 
    1. Identify the area where refrigerant leaks from, refer to ON-VEHICLE INSPECTION .
    2. Repair the identified area of the air conditioning system.
    3. Evacuate the air conditioning system.

    NEXT → See step   22 

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

      HINT: 

      Cooling Fan Circuit, refer to Cooling Fan Circuit .

    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 air conditioning system.
    3. Add an appropriate amount of refrigerant, refer to 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 DTCs.

    NEXT: Go to next step 

  15. CHECK DTC OUTPUT 
    1. Check for DTCs when the following conditions are satisfied.
      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)
      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 DTCs. If a 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. In this case, in order to complete the repair, it is necessary to replace the cooler dryer.

      Result

      Result Proceed to
      DTC B1423/23 is output A
      DTC B1423/23 is not output B

    B → See step   23 

    A: Go to next step 

  16. REPLACE EXPANSION VALVE 
    1. Replace the expansion valve with a normal one, refer to DISASSEMBLY .

      HINT: 

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

    NEXT: Go to next step 

  17. CHARGE REFRIGERANT 
    1. Add an appropriate amount of refrigerant, refer to REPLACEMENT .

    NEXT: Go to next step 

  18. CHECK DTC OUTPUT 
    1. Check for DTCs when the following conditions are satisfied.
      Item Condition
      Vehicle Doors Fully open
      Temperature Setting MAX COLD
      Blower Speed HI
      A/C Switch ON
      R/F Switch RECIRCULATE
      Interior Temperature 25 to 35°C (77 to 95°F)
      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 with dirt, dust or other contaminants. In this case, clean or replace the condenser or pipes.

      Result

      Result Proceed to
      DTC B1423/23 is not output A
      DTC B1423/23 is output B

    B → See step   24 

    A → END 

  19. PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  20. REPLACE AIR CONDITIONING PRESSURE SENSOR. Refer to  REMOVAL 
  21. REPLACE AIR CONDITIONING AMPLIFIER. Refer to  REMOVAL 
  22. CHARGE REFRIGERANT. Refer to  REPLACEMENT 
  23. CLEAN ON REPLACE CONDENSER OR PIPE. Refer to  REMOVAL 
  24. REPLACE CONDENSER. Refer to  REMOVAL 
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