DTC B1423/23: Pressure Sensor Circuit [10/2014 - ]: Procedure

1. Disconnect the A35 air conditioner pressure sensor connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A35-3 (+) - Body ground	Power switch on (IG)	4.75 to 5.25 V

Result: 

NG 

See step  5

Result: 

OK 

See step  2

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A35-1 (-) - Body ground	Always	Below 1 Ω

Result: 

NG 

See step  6

Result: 

OK 

See step  3

1. Reconnect the A35 air conditioner pressure sensor connector.
2. Remove the air conditioning amplifier assembly with the connectors still connected.

   Courtesy 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
   D62-9 (PRE) - Body ground	Power switch on (IG) (A/C: Off)	0.62 to 4.73 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.

Result: 

NG 

See step  7

Result: 

OK 

See step  4

1. Turn the power switch on (READY).
2. 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
   Recirculation/fresh 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 4.73 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 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 thermistor assembly and the No. 1 cooler thermistor 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.

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard Voltage

      Tester Connection	Condition	Specified Condition
      D62-9 (PRE) - Body ground	Power switch on (IG) (A/C: On)	0.62 to 4.73 V

      TEXT IN ILLUSTRATION
      
      

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

      Result

      Result	Proceed to
      OK (When troubleshooting according to the DTC)	A
      OK (When troubleshooting according to Problem Symptoms Table)	B
      NG	C

Result: 

A 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

B 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

(Refer to PROBLEM SYMPTOMS TABLE [10/2014 - 10/2015] or PROBLEM SYMPTOMS TABLE [10/2015 - ] )

Result: 

C 

See step  13

1. Disconnect the D62 air conditioning amplifier assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A35-3 (+) - D62-10 (S5-3)	Always	Below 1 Ω
   D62-10 (S5-3) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the D62 air conditioning amplifier assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A35-1 (-) - D62-13 (SG-2)	Always	Below 1 Ω
   D62-13 (SG-2) - Body ground	Always	10 kΩ or higher

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the A35 air conditioner pressure sensor connector.
2. Disconnect the D62 air conditioning amplifier assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A35-2 (PR) - D62-9 (PRE)	Always	Below 1 Ω
   D62-9 (PRE) - Body ground	Always	10 kΩ or higher

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  8

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.

   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.

Result: 

NG 

See step  12

Result: 

OK 

See step  9

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 [10/2014 - ] ).

   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 cooler 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.

Result: 

NEXT 

See step  10

1. Turn the power switch on (READY).
2. Recheck 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
   Recirculation/fresh 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 stored. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored 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 thermistor assembly and the No. 1 cooler thermistor 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 too much refrigerant when the level was insufficient. Therefore, identify and repair the area where refrigerant leaks from as necessary.

Result: 

B 

END 

Result: 

A 

See step  11

1. Install a manifold gauge set.
2. Reconnect the A35 air conditioner pressure sensor connector.
3. Turn the power switch on (IG).
4. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D62-9 (PRE) - D62-13 (SG-2)	Refrigerant pressure: Normal pressure (less than 3025 kPa (30.8 kgf/cm2 , 439 psi) and more than 176 kPa (1.8 kgf/cm2 , 26 psi))	0.62 to 4.73 V

   TEXT IN ILLUSTRATION
   
   

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

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

(Refer to REMOVAL [10/2014 - ] )

Result: 

NG 

REPLACE AIR CONDITIONER PRESSURE SENSOR 

(Refer to REMOVAL [10/2014 - ] )

1. Identify the area where refrigerant leaks from (Refer to REPLACEMENT [10/2014 - ] ).
2. Repair the identified area of the air conditioning system.
3. Evacuate the air conditioning system.

Result: 

NEXT 

CHARGE SYSTEM WITH REFRIGERANT 

(Refer to REPLACEMENT [10/2014 - ] )

1. Check that the cooling fan(s) operates normally.

   HINT: 

   Refer to cooling fan system (Refer to ON-VEHICLE INSPECTION [10/2014 - ] ).

Result: 

NG 

REPAIR COOLING FAN SYSTEM 

Result: 

OK 

See step  14

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 [10/2014 - ] ).

   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 cooler 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.

Result: 

NEXT 

See step  15

1. Turn the power switch on (READY).
2. Recheck 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
   Recirculation/fresh 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 stored. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored 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 thermistor assembly and the No. 1 cooler thermistor 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 cooler 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 DTCs are not output after this work, it indicates that the cooler dryer in the cooler condenser assembly 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	Proceed to
   DTC B1423/23 is output	A
   DTC B1423/23 is not output	B

Result: 

B 

REPLACE COOLER CONDENSER ASSEMBLY 

(Refer to REMOVAL [10/2014 - 10/2015] or REMOVAL [10/2015 - ] )

Result: 

A 

See step  16

1. Replace the cooler expansion valve with a new one (Refer to REMOVAL [10/2014 - ] ).

   HINT: 

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

Result: 

NEXT 

See step  17

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 [10/2014 - ] ).

   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 cooler 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.

Result: 

NEXT 

See step  18

1. Turn the power switch on (READY).
2. Recheck 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
   Recirculation/fresh 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 stored. It is necessary to measure the voltage for a certain amount of time (approximately 10 minutes) because the DTC may be stored 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 thermistor assembly and the No. 1 cooler thermistor 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 cooler expansion valve with a new or known good one, the cooler condenser assembly or pipes may be clogged due to dirt, dust or other foreign matter. In this case, clean or replace the cooler condenser assembly or pipes.

   Result

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

Result: 

A 

END 

Result: 

B 

CLEAN OR REPLACE COOLER CONDENSER ASSEMBLY OR PIPE