AIR CONDITIONING SYSTEM, Diagnostic DTC:B1411/11

DTC Code DTC Name
B1411/11 Room Temperature Sensor Circuit

DESCRIPTION

The room temperature sensor for the front seat is installed in the instrument panel to detect the room temperature and control the heater and air conditioner "AUTO" mode. The resistance of the room temperature sensor changes in accordance with the room temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier applies voltage (5 V) to the room temperature sensor and reads voltage changes as the resistance of the room temperature sensor changes. This sensor also sends the appropriate signals to the air conditioning amplifier.

DTC No. DTC Detection Condition Trouble Area
B1411/11 Open or short in room temperature sensor circuit

  • Room temperature sensor

  • Harness and connector between room temperature sensor and air conditioning amplifier

  • Air conditioning amplifier

WIRING DIAGRAM

A01GN3LE06

INSPECTION PROCEDURE

PROCEDURE


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


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

      Air Conditioner
      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Room Temperature Sensor

      Room temperature sensor /

      Min.: -6.5°C (20.3°F)

      Max.: 57.25°C (135.05°F)

      		 Actual room temperature for front seat is displayed

      Open in circuit: -6.5°C (20.3°F)

      Short in circuit: 57.25°C (135.05°F)
      OK
      The display is as specified in the normal condition.
      Result
      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 Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    A

  2. INSPECT ROOM TEMPERATURE SENSOR

    A01GNCHE09

    1. Remove the room temperature sensor Click here.

    2. 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
      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.

      Tech Tips

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


    NG

    REPLACE ROOM TEMPERATURE SENSOR Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (ROOM TEMPERATURE - AIR CONDITIONING AMPLIFIER)

    A01GNLXE01

    1. Disconnect the L37 room temperature sensor connector.

    2. Disconnect the L77 air conditioning amplifier connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      L37-2 - L77-9 (TR) Always Below 1 Ω
      L37-1 - L77-32 (SG-1) Always Below 1 Ω
      L77-9 (TR) - Body ground Always 10 kΩ or higher
      L77-32 (SG-1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here