DTC B1423: Open in Pressure Sensor Circuit / Abnormal Refrigerant Pressure [10/2018 - 07/2022]: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Body Electrical / Air Conditioner / Data List.
5. Read the Data List according to the display on the Techstream.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Regulator Pressure Sensor	Air conditioner pressure sensor	Min.: -66.2 psi (gauge) Max.: 478.0 psi (gauge)	Actual refrigerant pressure displayed	Refrigerant line (gas leak etc.) Air conditioner pressure sensor circuit malfunction

   Body Electrical > Air Conditioner > Data List 

   Tester Display
   Regulator Pressure Sensor

6. Install a manifold gauge set.

   Refer to ON-VEHICLE INSPECTION [10/2018 - 07/2022]

7. Read the manifold gauge set with the following conditions met.
   MEASUREMENT CONDITION:
   
   

   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)

   Standard Pressure

   Low pressure side 

   150 to 250 kPa (1.5 to 2.5 kgf/cm² , 22 to 36 psi)

   High pressure side 

   1370 to 1570 kPa (14 to 16 kgf/cm² , 199 to 228 psi)

8. Compare the values displayed in the Data List and on the manifold gauge set.

   OK

   The values displayed in the Data List and on the manifold gauge set match.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  7

Result: 

OK 

See step  2

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Enter the following menus: Body Electrical / Air Conditioner / Data List.
4. Read the Data List according to the display on the Techstream.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Refrigerant High Pressure History	Refrigerant high pressure history	Min.: 0 Max.: 255	Number of times refrigerant high pressure history stored displayed	-

   Body Electrical > Air Conditioner > Data List 

   Tester Display
   Refrigerant High Pressure History

   Result

   Result	Proceed to
   The value is 0	A
   The value is not 0	B

Result: 

A 

INSPECT REFRIGERANT PRESSURE WITH MANIFOLD GAUGE SET. Refer to  ON-VEHICLE INSPECTION [10/2018 - 07/2022] 

Result: 

B 

See step  3

1. Check if the cooling fan operates normally.

   Refer to ON-VEHICLE INSPECTION [10/2018 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO COOLING FAN SYSTEM. Refer to  Cooling Fan Circuit [10/2018 - ] 

Result: 

OK 

See step  4

1. Recover the refrigerant from the air conditioning system using a refrigerant recovery unit.

   Refer to REPLACEMENT [10/2018 - 07/2022]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

Refer to REPLACEMENT [10/2018 - 07/2022]

Result

Result: 

NEXT 

See step  6

1. Clear the refrigerant high pressure history stored in the air conditioning amplifier assembly.

   Refer to UTILITY [10/2018 - 07/2022]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

END 

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A25-3 (+) - Body ground	Power switch on (IG)	4.75 to 5.25 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  12

Result: 

OK 

See step  8

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A25-1 (-) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  11

Result: 

OK 

See step  9

1. Disconnect the F50 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
   A25-2 (PR) - F50-24 (PRE)	Always	Below 1 Ω
   A25-2 (PR) or F50-24 (PRE) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  10

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Connect all the connectors.
2. Measure the voltage with the following conditions met.
   MEASUREMENT CONDITION:
   
   

   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 4.61 V), a fail-safe function will stop compressor operation. In this case, make sure to measure the voltage before the fail-safe function operates.
   • 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 ambient air temperature is low (below -1.5°C (29.3°F)), the compressor with motor assembly will be stopped, due to inputs of the thermistor assembly and 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.

      Standard Voltage

      Tester Connection	Switch Condition	Specified Condition
      F50-24 (PRE) - Body ground	Power switch on (IG) (A/C switch: On)	0.74 to 4.61 V*

      *: While sensor voltage is 5 V.

3. Connect the Techstream to the DLC3.
4. Turn the power switch on (IG).
5. Turn the Techstream on.
6. Enter the following menus: Body Electrical / Air Conditioner / Data List.
7. Read the Data List according to the display on the Techstream.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Regulator Pressure Sensor	Air conditioner pressure sensor	Min.: -66.2 psi (gauge) Max.: 478.0 psi (gauge)	Actual refrigerant pressure displayed	Refrigerant line (gas leak etc.) Air conditioner 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.)
   NG (The voltage does not change.)	B

Result: 

A 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

B 

REPLACE AIR CONDITIONER PRESSURE SENSOR. Refer to  REMOVAL [10/2018 - ] 

1. Disconnect the F50 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
   A25-1 (-) - F50-3 (SG-4)	Always	Below 1 Ω
   A25-1 (-) or F50-3 (SG-4) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the F50 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
   A25-3 (+) - F50-6 (S5-3)	Always	Below 1 Ω
   A25-3 (+) or F50-6 (S5-3) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR