DTC B1412/12: Ambient Temperature Sensor Circuit [11/2016 - ]: 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. Check the value(s) by referring to the table below.

   Body Electrical > Air Conditioner > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Ambient Temp Sensor	Thermistor assembly	Min.: -23.30°C (-9.94°F) Max.: 65.95°C (150.71°F)	Actual ambient temperature displayed	-

   Body Electrical > Air Conditioner > Data List 

   Tester Display
   Ambient Temp Sensor

   OK

   The display is as specified in the normal condition column.

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [02/2014 - ] 

Result:  2

NG 

See step  2

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the thermistor assembly.

   Refer to REMOVAL [02/2014 - ]

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

   Standard Resistance

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

   NOTE:

   • Hold the sensor only by its connector. Touching the sensing portion may change the resistance value.
   • When measuring, the sensor temperature must be the same as the ambient temperature.

   HINT: 

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

   Result

   Proceed to
   OK
   NG

Result:  2

NG 

REPLACE THERMISTOR ASSEMBLY. Refer to  REMOVAL [02/2014 - ] 

Result:  1

OK 

See step  3

1. Disconnect the F80 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
   A79-2 (+) - F80-5 (TAM)	Always	Below 1 Ω
   A79-1 (-) - F80-13 (SG-2)	Always	Below 1 Ω
   A79-2 (+) or F80-5 (TAM) - Body ground	Always	10 kΩ or higher
   A79-1 (-) or F80-13 (SG-2) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result:  1

OK 

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [02/2014 - ] 

Result:  2

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR