AIR CONDITIONING SYSTEM, Diagnostic DTC:B1411/11

DTC Code DTC Name
B1411/11 Room Temperature Sensor Circuit

DESCRIPTION

The cooler thermistor (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 front room 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 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 assembly.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

Note

B1411/11

Room Temperature Sensor Circuit

An open or short in the cooler thermistor (room temperature sensor) circuit.

  • Cooler thermistor (room temperature sensor)

  • Harness or connector

  • Air conditioning amplifier assembly

Stored

(4 seconds or more)

If the front room temperature is approx. -18.6°C (-1.48°F) or less, DTC B1411/11 may be stored even though the system is normal.

WIRING DIAGRAM

E156584E74

PROCEDURE

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

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

      Click here

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Room Temperature Sensor

      Cooler thermistor (room temperature sensor)

      Min.: -6.5°C (20.3°F)

      Max.: 57.25°C (135.05°F)

      Actual room temperature for front seat displayed

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

      Short in the circuit: 57.25°C (135.05°F).

      OK

      The display is as specified in the normal condition column.

    Result

    Result

    Proceed to

    OK (When troubleshooting according to problem symptoms table)

    A

    OK (When troubleshooting according to the DTC)

    B

    NG

    C
    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click here

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    C

  2. INSPECT COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

    1. E248056C01

      *a

      Sensing Portion

      *b

      Resistance

      *c

      Allowable Range

      *d

      Temperature

      Remove the cooler thermistor (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

      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:

      • 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.

      Tip:

      As the temperature increases, the resistance decreases (refer to the graph).

    Result

    Result

    OK

    NG
    NG

    REPLACE COOLER THERMISTOR (ROOM TEMPERATURE SENSOR)

    Click here

    OK

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

    1. Disconnect the G15 sensor connector.

    2. Disconnect the G13 amplifier connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G15-1 - G13-29 (TR)

      Always

      Below 1 Ω

      G15-2 - G13-34 (SG-1)

      G13-29 (TR) - Body ground

      Always

      10 kΩ or higher

      G13-34 (SG-1) - Body ground

    Result

    Result

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR