Inspection Procedure

1. Use the Data List to check if the ambient temperature sensor is functioning properly.
   1. Intelligent tester

      AIR CONDITIONER 

      INTELLIGENT TESTER - AIR CONDITIONER REFERENCE CHART
      
      

      Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
      AMBI TEMP SENS	Ambient temperature sensor / Min: -23.3°C (-9.94°F) Max: 65.95°C (150.71°F)	Actual ambient temperature is displayed	Open in circuit: -23.3°C (-9.94°F) Short in circuit: 65.95°C (150.71 °F)

   2. Techstream

      Air Conditioner 

      TECHSTREAM - AIR CONDITIONER REFERENCE CHART
      
      

      Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
      Ambient Temp Sensor	Ambient temperature sensor / Min: -23.3°C (-9.94°F) Max: 65.95°C (150.71 °F)	Actual ambient temperature is displayed	Open in circuit: -23.3°C (-9.94°F) Short in circuit: 65.95°C (150.71 °F)

      OK: The display is as specified in the normal condition. 

      Result 

      RESULT CHART
      
      

      Result	Proceed to
      NG	A
      OK (Checking from the PROBLEM SYMPTOMS TABLE)	B
      OK (Checking from the DTC)	C

B: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See  PROBLEM SYMPTOMS TABLE   ) 

C: REPLACE AIR CONDITIONING AMPLIFIER (See  REMOVAL   ) 

A: GO TO NEXT STEP 

1. Remove the ambient temperature sensor (see REMOVAL  ).
2. Measure the resistance according to the value(s) in the table below.
   Fig 1: Inspecting Ambient Temperature Sensor

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance 

   AMBIENT TEMPERATURE SENSOR
   
   

   Tester Connection	Condition	Specified Condition
   1 - 2	10°C (50°F)	3.00 to 3.73 kΩ
   1 - 2	15°C (59°F)	2.45 to 2.88 kΩ
   1 - 2	20°C (68°F)	1.95 to 2.30 kΩ
   1 - 2	25°C (77°F)	1.60 to 1.80 kΩ
   1 - 2	30°C (86°F)	1.28 to 1.47 kΩ
   1 - 2	35°C (95°F)	1.00 to 1.22 kΩ
   1 - 2	40°C (104°F)	0.80 to 1.00 kΩ
   1 - 2	45°C (113°F)	0.65 to 0.85 kΩ
   1 - 2	50°C (122°F)	0.50 to 0.70 kΩ
   1 - 2	55°C (131°F)	0.44 to 0.60 kΩ
   1 - 2	60°C (140°F)	0.36 to 0.50 kΩ

   NOTE:

   • Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
   • When measuring, the sensor temperature must be the same as the ambient temperature.

   HINT:

   As the temperature increases, the resistance decreases (see the graph in Fig 1).

NG: REPLACE AMBIENT TEMPERATURE SENSOR (See  REMOVAL   ) 

OK: GO TO NEXT STEP 

Fig 2: Checking Harness And Connector (Ambient Temperature Sensor - Front Light ECU)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the B5 ambient temperature sensor connector.
2. Disconnect the B14 front light ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   AMBIENT TEMPERATURE SENSOR - FRONT LIGHT ECU
   
   

   Tester Connection	Condition	Specified Condition
   B5-1 - B14-20 (TM)	Always	Below 1 Ω
   B5-2 - B14-19 (TME)	Always	Below 1 Ω
   B14-20 (TM)- Body ground	Always	10 kΩ or higher
   B14-19 (TME) -Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE FRONT LIGHT ECU