Dtc B1412/12 Ambient Temperature Sensor Circuit

Vehicle Interior. Land Cruiser. Urj200, 202 Grj200 Vdj200
Heating Air Conditioning. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (AMBIENT TEMPERATURE SENSOR)

INSPECT AMBIENT TEMPERATURE SENSOR

CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

DTC B1412/12 Ambient Temperature Sensor Circuit


DESCRIPTION

The ambient temperature sensor is installed in the front part of the condenser to detect the ambient temperature and control the air conditioner "auto" mode. The sensor connected to the air conditioning amplifier assembly detects fluctuations in the ambient temperature. This data is used for controlling the room temperature. The sensor sends a signal to the air conditioning amplifier assembly. The resistance of the ambient temperature sensor changes in accordance with the ambient temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The air conditioning amplifier assembly applies voltage (5 V) to the ambient temperature sensor and reads voltage changes as the resistance of the ambient temperature sensor changes.

DTC Code
DTC Detection Condition
Trouble Area
B1412/12
An open or short in the ambient temperature sensor circuit.
  1. Ambient temperature sensor
  2. Harness or connector between ambient temperature sensor and air conditioning amplifier assembly
  3. Air conditioning amplifier assembly

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1412/12 Ambient Temperature Sensor Circuit


Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1412/12 Ambient Temperature Sensor Circuit


INSPECTION PROCEDURE

1.READ VALUE USING INTELLIGENT TESTER (AMBIENT TEMPERATURE SENSOR)

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

    Air Conditioner
    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 displayed
    		Open in the circuit: -23.3°C (-9.94°F).
    Short in the circuit: 65.95°C (150.71°F).
    OK:
    The display is as specified in the normal condition.


NG
Go to step 2
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)

2.INSPECT AMBIENT TEMPERATURE SENSOR
Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1412/12 Ambient Temperature Sensor Circuit

  1. Remove the ambient temperature sensor (Click here).

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1 (+) - 2 (-)
    		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
    NOTICE:
    1. Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
    2. When measuring, the sensor temperature must be the same as the ambient temperature.
    HINT:
    As the temperature increases, the resistance decreases (see the graph).


NG
REPLACE AMBIENT TEMPERATURE SENSOR (Click here)
OK


3.CHECK HARNESS AND CONNECTOR (AMBIENT TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)
Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1412/12 Ambient Temperature Sensor Circuit

  1. w/ Rear Heater

    1. Disconnect the A14 sensor connector.

    2. Disconnect the E35 amplifier connector.

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

      Standard Resistance:
      Tester Connection
      		Condition
      		Specified Condition
      A14 (+) -1 - E35-10 (TAM)
      		Always
      		Below 1 Ω
      A14-2 (-) - E35-16 (SG-2)
      E35-10 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      E35-16 (SG-2) - Body ground


    Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1412/12 Ambient Temperature Sensor Circuit

  1. w/o Rear Heater

    1. Disconnect the A14 sensor connector.

    2. Disconnect the E81 amplifier connector.

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

      Standard Resistance:
      Tester Connection
      		Condition
      		Specified Condition
      A14-1 (+) - E81-5 (TAM)
      		Always
      		Below 1 Ω
      A14-2 (-) - E81-13 (SG-2)
      E81-5 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      E81-13 (SG-2) - Body ground


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)