AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:11

DTC Code DTC Name
11 Room Temperature Sensor Circuit

DESCRIPTION

The cooler thermistor is installed in the instrument panel to detect the room temperature and control the heater and air conditioning AUTO function. The resistance of the cooler thermistor 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 assembly applies voltage (5 V) to the cooler thermistor and reads voltage changes as the resistance of the cooler thermistor changes.

DTC Code DTC Detection Condition Trouble Area
11 An open or short in the room temperature sensor circuit.

  • Cooler thermistor

  • Air conditioning amplifier assembly

  • Harness or connector

WIRING DIAGRAM

A01DWZEE03

INSPECTION PROCEDURE

PROCEDURE


  1. INSPECT COOLER THERMISTOR


    1. A01E2OBE02
      Text in Illustration
      *a Resistance (kΩ)
      *b Temperature

      Remove the 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
      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 cooler thermistor may change the resistance value. Be sure to hold the connector of the cooler thermistor.

      • When measuring the resistance, the cooler thermistor temperature must be the same as the ambient temperature.

      Tech Tips

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


    NG

    REPLACE COOLER THERMISTOR Click here

    OK

  2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A01DVCGE08
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected Click here.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A46-18 (TR) - A46-13 (SG-3)

      • Ignition switch ON

      • Cabin temperature 25°C (77°F)

      		 1.8 to 2.2 V

      • Ignition switch ON

      • Cabin temperature 40°C (104°F)

      		 1.2 to 1.6 V

      Tech Tips

      As the temperature increases, the voltage decreases.

      Result
      Result Proceed to
      OK (When troubleshooting according to problem symptoms table.) A
      OK (When troubleshooting according to DTC.) B
      NG C

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR - AIR CONDITIONING AMPLIFIER) Click here

    A

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

  3. CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR - AIR CONDITIONING AMPLIFIER)


    1. Disconnect the A34 cooler thermistor connector.

    2. Disconnect the A46 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-18 (TR) - A34-2 Always Below 1 Ω
      A46-13 (SG-3) - A34-1
      A46-18 (TR) - Body ground Always 10 kΩ or higher
      A46-13 (SG-3) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here