Pressure Sensor Circuit [03/2017 - ]: Procedure

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A18 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
   A18-3 (+) - Body ground	Ignition switch ON	4.75 to 5.25 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  6

Result: 

OK 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A18-1 (-) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  5

Result: 

OK 

See step  3

1. Disconnect the K55 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
   A18-2 (PR) - K55-24 (PRE)	Always	Below 1 Ω
   A18-2 (PR) or K55-24 (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  4

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. 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 pulley 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	Condition	Specified Condition
      K55-24 (PRE) - Body ground	Ignition switch ON (A/C switch: On)	0.74 to 4.61 V

2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Body Electrical / Air Conditioner / Data List.
6. 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.: -456.68 kPaG Max.: 3294.37 kPaG	Actual refrigerant pressure displayed	-

   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 [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - ] 

Result: 

B 

REPLACE AIR CONDITIONER PRESSURE SENSOR. Refer to  REMOVAL [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - 10/2020]  , or refer to  REMOVAL [10/2020 - ] 

1. Disconnect the K55 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
   K55-3 (SG-4) - A18-1 (-)	Always	Below 1 Ω
   K55-3 (SG-4) or A18-1 (-) - 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 [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Disconnect the K55 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
   K55-6 (S5-3) - A18-3 (+)	Always	Below 1 Ω
   K55-6 (S5-3) or A18-3 (+) - 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 [03/2017 - 06/2017]  , or refer to  REMOVAL [06/2017 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR