AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1413/13

DTC Code DTC Name
B1413/13 Evaporator Temperature Sensor Circuit

DESCRIPTION

The front evaporator temperature sensor (No. 1 cooler thermistor) is installed on the evaporator in the air conditioner unit to detect the temperature of the cooled air that has passed through the evaporator and to control the air conditioner. It sends signals to the air conditioning amplifier, which change in accordance with the resistance of the front evaporator temperature sensor (No. 1 cooler thermistor). As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier applies a voltage (5 V) to the front evaporator temperature sensor (No. 1 cooler thermistor) and reads voltage changes as changes in the resistance of the front evaporator temperature sensor (No. 1 cooler thermistor). This sensor is used for frost prevention.

DTC No. DTC Detection Condition Trouble Area
B1413/13 Open or short in evaporator temperature sensor circuit

  • Front evaporator temperature sensor (No. 1 cooler thermistor)

  • Harness and connector between front evaporator temperature sensor (No. 1 cooler thermistor) and air conditioning amplifier

  • Air conditioning amplifier

WIRING DIAGRAM

A011A3AE04

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (EVAPORATOR FIN THERMISTOR)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. According to the display on the intelligent tester, read the Data List.

      Air Conditioner
      Item Measurement Item/Display (Range) Normal Condition Diagnostic Note
      Evaporator Fin Thermistor

      Evaporator temperature sensor / Min.: -29.7°C (-21.46°F)

      Max.: 59.55°C (139.019°F)

      		 Actual evaporator temperature is displayed

      Open circuit: -29.7°C (-21.46°F)

      Short circuit: 59.55°C (139.019°F)
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (When troubleshooting according to the Problem Symptoms Table) B
      OK (When troubleshooting according to the DTC output) C

    B

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

    C

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    A

  2. INSPECT FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR)

    A0119QOE01

    1. Remove the front evaporator temperature sensor (No. 1 cooler thermistor).

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 - 2 -10°C (14°F) 7.30 to 9.10 kΩ
      -5°C (23°F) 5.65 to 6.95 kΩ
      0°C (32°F) 4.40 to 5.35 kΩ
      5°C (41°F) 3.40 to 4.15 kΩ
      10°C (50°F) 2.70 to 3.25 kΩ
      15°C (59°F) 2.14 to 2.58 kΩ
      20°C (68°F) 1.71 to 2.05 kΩ
      25°C (77°F) 1.38 to 1.64 kΩ
      30°C (86°F) 1.11 to 1.32 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).

    3. Reinstall the front evaporator temperature sensor (No. 1 cooler thermistor).


    NG

    REPLACE FRONT EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR) Click here

    OK

  3. INSPECT AIR CONDITIONING HARNESS


    1. A0117VRE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (Air Conditioner Harness)
      *2 Front Evaporator Temperature Sensor (No. 1 Cooler Thermistor) Side
      *3 Air Conditioning Amplifier Side

      Remove the air conditioning harness Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (SGB) - z1-5 (SG) Always Below 1 Ω
      2 (TEB) - z1-6 (TE) Always Below 1 Ω
      1 (SGB) - Body ground Always 10 kΩ or higher
      2 (TEB) - Body ground Always 10 kΩ or higher

    3. Reinstall the air conditioning harness.


    NG

    REPLACE AIR CONDITIONING HARNESS Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here