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 GTS (AMBIENT TEMP SENSOR)

INSPECT COOLER THERMISTOR (AMBIENT TEMPERATURE SENSOR)

CHECK COOLER THERMISTOR [AMBIENT TEMPERATURE SENSOR] - AIR CONDITIONING AMPLIFIER ASSEMBLY

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. Cooler thermistor (ambient temperature sensor)
  2. Harness or connector
  3. Air conditioning amplifier assembly

WIRING DIAGRAM


w/ Rear Heater:

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


w/o Rear Heater:

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 GTS (AMBIENT TEMP SENSOR)

  1. Use the Data List to check if the cooler thermistor (ambient temperature sensor) is functioning properly (Click here).

    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
    		Thermistor assembly (ambient temperature sensor) system malfunction:
    1. Open in the circuit: -23.3°C (-9.94°F)
    2. Short in the circuit: 65.95°C (150.71°F)
    OK:
    The display is as specified in the normal condition.
    Result
    Result
    		Proceed to
    OK (When troubleshooting according to the DTC)
    		A
    OK (When troubleshooting according to Problem Symptoms Table)
    		B
    NG
    		C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)

C
Go to step 2
A

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)

2.INSPECT COOLER THERMISTOR (AMBIENT TEMPERATURE SENSOR)

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

  1. Inspect the cooler thermistor (ambient temperature sensor) (Click here).



NG
REPLACE COOLER THERMISTOR (AMBIENT TEMPERATURE SENSOR) (Click here)
OK


3.CHECK COOLER THERMISTOR [AMBIENT TEMPERATURE SENSOR] - AIR CONDITIONING AMPLIFIER ASSEMBLY
  1. *1: w/o Door Ajar Warning Buzzer
    *2: w/ Door Ajar Warning Buzzer

  1. w/ Rear Heater:

    1. Disconnect the A14*1 or A85*2 cooler thermistor (ambient temperature sensor) connector.

    2. Disconnect the E35 air conditioning amplifier assembly connector.

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

      Standard Resistance:
      w/o Door Ajar Warning Buzzer:
      Tester Connection
      		Condition
      		Specified Condition
      A14-1 - E35-10 (TAM)
      		Always
      		Below 1 Ω
      A14-2 - E35-32 (SG-2)
      		Always
      		Below 1 Ω
      A14-1 - A14-2
      		Always
      		10 kΩ or higher
      A14-1 or E35-10 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      A14-2 or E35-32 (SG-2) - Body ground
      		Always
      		10 kΩ or higher
      w/ Door Ajar Warning Buzzer:
      Tester Connection
      		Condition
      		Specified Condition
      A85-1 - E35-10 (TAM)
      		Always
      		Below 1 Ω
      A85-2 - E35-32 (SG-2)
      		Always
      		Below 1 Ω
      A85-1 - A85-2
      		Always
      		10 kΩ or higher
      A85-1 or E35-10 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      A85-2 or E35-32 (SG-2) - Body ground
      		Always
      		10 kΩ or higher

  1. w/o Rear Heater:

    1. Disconnect the A14*1 or A85*2 cooler thermistor (ambient temperature sensor) connector.

    2. Disconnect the E81 air conditioning amplifier assembly connector.

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

      Standard Resistance:
      w/o Door Ajar Warning Buzzer:
      Tester Connection
      		Condition
      		Specified Condition
      A14-1 - E81-5 (TAM)
      		Always
      		Below 1 Ω
      A14-2 - E81-13 (SG-2)
      		Always
      		Below 1 Ω
      A14-1 - A14-2
      		Always
      		10 kΩ or higher
      A14-1 or E81-5 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      A14-2 or E81-13 (SG-2) - Body ground
      		Always
      		10 kΩ or higher
      w/ Door Ajar Warning Buzzer:
      Tester Connection
      		Condition
      		Specified Condition
      A85-1 - E81-5 (TAM)
      		Always
      		Below 1 Ω
      A85-2 - E81-13 (SG-2)
      		Always
      		Below 1 Ω
      A85-1 - A85-2
      		Always
      		10 kΩ or higher
      A85-1 or E81-5 (TAM) - Body ground
      		Always
      		10 kΩ or higher
      A85-2 or E81-13 (SG-2) - Body ground
      		Always
      		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)