Dtc B1423/23 Pressure Sensor Circuit

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (PRESSURE SENSOR - BATTERY AND BODY GROUND)

CHECK AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT)

CHECK AIR CONDITIONER PRESSURE SENSOR (SENSOR SIGNAL CIRCUIT)

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

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

CHECK FOR AIR CONDITIONING SYSTEM LEAK

CHARGE REFRIGERANT

CHECK FOR DTC

CHECK AIR CONDITIONER PRESSURE SENSOR

REPAIR AIR CONDITIONING SYSTEM LEAK

CHARGE REFRIGERANT

CHECK FOR DTC

REPLACE COOLER EXPANSION VALVE

CHARGE REFRIGERANT

CHECK FOR DTC

DESCRIPTION

HINT:

Be sure to check the refrigerant volume first when this DTC is output because this DTC may also be stored if there is no refrigerant in the cycle.

WIRING DIAGRAM

INSPECTION PROCEDURE

1. Disconnect the A2 sensor connector.
   

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   A2-3 (+) - Body ground	Ignition switch ON	4.75 to 5.25 V

3. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A2-1 (-) - Body ground	Always	Below 1 Ω

1. Reconnect the A2 sensor connector.
   

2. Remove the air conditioning amplifier assembly with its connectors still connected (LandCruiser RM0000039R5028X.html).
   

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   G25-9 (PRE) - Body ground	Ignition switch ON A/C switch off	0.63 to 4.72 V

   Text in Illustration

   *a	Component with harness connected (Air Conditioning Amplifier Assembly)

   HINT:

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

1. Measure the voltage when the following conditions are met.
   

   Measurement Condition

   Item	Condition
   Engine Speed	2000 rpm
   Vehicle Doors	Fully open
   Temperature Setting	MAX COOL
   Blower Speed	Hi
   A/C Switch	On
   R/F Switch	Recirculation
   Interior Temperature	25 to 35°C (77 to 95°F)

   NOTICE:

   1. If refrigerant pressure on the high pressure side becomes extremely high during the inspection (the voltage exceeds 4.8 V), the fail-safe function stops compressor operation. Therefore, measure the voltage before the fail-safe operation.
      
   2. 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 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:

      Tester Connection	Condition	Specified Condition
      G25-9 (PRE) - Body ground	Above measurement condition	0.63 to 4.72 V

      Text in Illustration

      *a	Component with harness connected (Air Conditioning Amplifier Assembly)

      Result

      Result	Proceed to
      OK (When troubleshooting according to problem symptoms table)	A
      OK (When troubleshooting according to the DTC)	B
      NG	C

1. Disconnect the G25 amplifier connector.
   

2. Disconnect the A2 sensor connector.
   

3. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A2-1 (-) - G25-13 (SG-2)	Always	Below 1 Ω
   A2-3 (+) - G25-10 (S5-3)	Always	Below 1 Ω
   G25-13 (SG-2) - Body ground	Always	10 kΩ or higher
   G25-10 (S5-3) - Body ground	Always	10 kΩ or higher

1. Disconnect the G25 amplifier connector.
   

2. Disconnect the A2 sensor connector.
   

3. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A2-2 (PR) - G25-9 (PRE)	Always	Below 1 Ω
   G25-9 (PRE) - Body ground	Always	10 kΩ or higher

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.

1. Add an appropriate amount of refrigerant (LandCruiser RM000001R8Y04UX.html).
   

1. Check for DTCs when the following conditions are met (LandCruiser RM000002LIT049X.html).
   

   Measurement Condition

   Item	Condition
   Engine Speed	2000 rpm
   Vehicle Doors	Fully open
   Temperature Setting	MAX COOL
   Blower Speed	Hi
   A/C Switch	On
   R/F Switch	Recirculation
   Interior Temperature	25 to 35°C (77 to 95°F)

   NOTICE:

   If refrigerant pressure on the high pressure side becomes high, a DTC will be stored. Therefore, it is necessary to check for DTCs after a certain amount of time (approximately 10 minutes) has passed because the DTC may be stored after the air conditioning system 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 evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.

   OK:

   DTC B1423 is not output.
   

   NOTICE:

   If the DTC was stored 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 leakage. Therefore, identify and repair the area where refrigerant leaks as necessary. The root cause of excessive refrigerant may be adding too much refrigerant.

1. Install a manifold gauge set.
   

2. Reconnect the A2 sensor connector.
   

3. Remove the air conditioning amplifier assembly with its connectors still connected (LandCruiser RM0000039R5028X.html).
   

4. Turn the ignition switch to ON.
   

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   G25-9 (PRE) - G25-13 (SG-2)	Ignition switch ON Refrigerant pressure normal (below 3.025 MPa [30.9 kgf/cm2, 438.6 psi] and higher than 0.176 MPa [1.8 kgf/cm2, 25.5 psi])	0.63 to 4.72 V
   	Ignition switch ON Refrigerant pressure abnormal (below 0.176 MPa [1.8 kgf/cm2, 25.5 psi])	Below 0.63 V
   	Ignition switch ON Refrigerant pressure abnormal (higher than 3.025 MPa [30.9 kgf/cm2, 438.6 psi])	4.72 V or higher

   Text in Illustration

   *a	Component with harness connected (Air Conditioning Amplifier Assembly)

1. Identify the area where refrigerant leaks (LandCruiser RM000001R8Y04UX.html).
   

2. Repair the identified area of the air conditioning system.
   

3. Evacuate the air conditioning system.
   

1. Use a refrigerant recovery unit to recover refrigerant.
   

2. Evacuate the air conditioning system.
   

3. Add an appropriate amount of refrigerant (LandCruiser RM000001R8Y04UX.html).
   

   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 then check for the DTC.

1. Check for DTCs when the following conditions are met (LandCruiser RM000002LIT049X.html).
   

   Measurement Condition

   Item	Condition
   Engine Speed	2000 rpm
   Vehicle Doors	Fully open
   Temperature Setting	MAX COOL
   Blower Speed	Hi
   A/C Switch	On
   R/F Switch	Recirculation
   Interior Temperature	25 to 35°C (77 to 95°F)

   NOTICE:

   If refrigerant pressure on the high pressure side becomes high, a DTC will be stored. Therefore, it is necessary to check for DTCs after a certain amount of time (approximately 10 minutes) has passed because the DTC may be stored after the air conditioning system operates for a while.

   HINT:

   1. 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 evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
      
   2. 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 procedure, it indicates that the cooler dryer in the cooler condenser assembly is not able to absorb moisture in the refrigerant cycle. In this case, to complete the repair, it is necessary to replace the cooler dryer.
      

   OK:

   DTC B1423 is not output.
   

1. Replace the cooler expansion valve with a new or normally functioning one (LandCruiser RM000003AXS04FX.html).
   

   HINT:

   Replace the cooler expansion valve with a new or normally functioning one because the cooler expansion valve is either stuck or clogged.

1. Add an appropriate amount of refrigerant (LandCruiser RM000001R8Y04UX.html).
   

1. Check for DTCs when the following conditions are met.
   

   Measurement Condition

   Item	Condition
   Engine Speed	2000 rpm
   Vehicle Doors	Fully open
   Temperature Setting	MAX COOL
   Blower Speed	Hi
   A/C Switch	On
   R/F Switch	Recirculation
   Interior Temperature	25 to 35°C (77 to 95°F)

   NOTICE:

   If refrigerant pressure on the high pressure side becomes high, a DTC will be stored. Therefore, it is necessary to check for DTCs after a certain amount of time (approximately 10 minutes) has passed because the DTC may be stored after the air conditioning system operates for a while.

   HINT:

   1. 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 evaporator temperature sensor to prevent the evaporator from freezing. In this case, perform the inspection in a warm indoor environment.
      
   2. If refrigerant pressure is not normal after replacing the expansion valve with a new or normally functioning one, the cooler condenser assembly or pipes may be clogged due to dirt, dust or other contaminants. In this case, clean or replace the cooler condenser assembly or pipes.
      

   OK:

   DTC B1423 is not output.