AIR CONDITIONING SYSTEM, Diagnostic DTC:B1411/11

DTC Code DTC Name
B1411/11 Room Temperature Sensor Circuit

DESCRIPTION

The room temperature sensor (cooler thermistor) is installed in the instrument panel. It detects the cabin temperature to control air conditioning AUTO mode. The resistance of the room temperature sensor (cooler thermistor) changes in accordance with the cabin 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 room temperature sensor (cooler thermistor) and reads voltage changes as the resistance of the room temperature sensor (cooler thermistor) changes. This sensor also sends appropriate signals to the air conditioning amplifier assembly.

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

  • Room temperature sensor (cooler thermistor)

  • Harness or connector between room temperature sensor (cooler thermistor) and air conditioning amplifier assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A00420BE16

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    5. Check the value(s) by referring to the table below.

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

      Room temperature sensor (cooler thermistor) /

      Min.: -6.50°C (20.30°F)

      Max.: 57.25°C (135.05°F)

      		 Actual cabin temperature displayed -
      OK
      The display is as specified in the Normal Condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to Problem Symptoms Table) B
      OK (When troubleshooting according to the DTC) C

    B

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

  2. INSPECT ROOM TEMPERATURE SENSOR (COOLER THERMISTOR)


    1. A0043QVE60
      Text in Illustration
      *1 Sensing Portion
      *2 Resistance (kΩ)
      *3 Allowable Range
      *4 Temperature (°C (°F))
      *a

      Component without harness connected

      (Room Temperature Sensor (Cooler Thermistor))

      Remove the room temperature sensor (cooler thermistor) 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


      • Hold the sensor only by its connector. Touching the sensor may change the resistance value.

      • 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 (COOLER THERMISTOR) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (ROOM TEMPERATURE SENSOR (COOLER THERMISTOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the L14 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
      L14-29 (TR) - L34-1 Always Below 1 Ω
      L14-34 (SG-1) - L34-2 Always Below 1 Ω
      L14-29 (TR) - Body ground Always 10 kΩ or higher
      L14-34 (SG-1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here