AIR CONDITIONING SYSTEM (for Manual Air Conditioning System), Diagnostic DTC:B1413

DTC Code DTC Name
B1413 Evaporator Temperature Sensor Circuit

DESCRIPTION

The evaporator temperature sensor (No. 1 cooler thermistor) is installed on the evaporator in the air conditioner unit to detect the temperature of the air that has passed through the evaporator and is used to control the air conditioning. It sends signals to the air conditioning amplifier assembly. The resistance of the evaporator temperature sensor (No. 1 cooler thermistor) changes in accordance with the cooled air temperature that has passed through the evaporator. 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 evaporator temperature sensor (No. 1 cooler thermistor) and reads voltage changes as the resistance of the evaporator temperature sensor (No. 1 cooler thermistor) changes. This sensor is used for frost prevention.

DTC No. DTC Detection Condition Trouble Area
B1413 Open or short in evaporator temperature sensor (No. 1 cooler thermistor) circuit

  • Evaporator temperature sensor (No. 1 cooler thermistor)

  • Air conditioning harness assembly

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A011V30E09

INSPECTION PROCEDURE

PROCEDURE

  1. READ VALUE USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the Techstream 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
      Evaporator Temp Sensor

      Evaporator temperature sensor (No. 1 cooler thermistor) /

      Min.: -29.70°C (-21.46°F)

      Max.: 59.55°C (139.19°F)

      		 Actual evaporator 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 EVAPORATOR TEMPERATURE SENSOR (NO. 1 COOLER THERMISTOR)

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

    2. Disconnect the a1 evaporator temperature sensor (No. 1 cooler thermistor) connector.

      A011UXOE88

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      a1-1 - a1-2 -10°C (14°F) 7.30 to 9.10 kΩ
      a1-1 - a1-2 -5°C (23°F) 5.65 to 6.95 kΩ
      a1-1 - a1-2 0°C (32°F) 4.40 to 5.35 kΩ
      a1-1 - a1-2 5°C (41°F) 3.40 to 4.15 kΩ
      a1-1 - a1-2 10°C (50°F) 2.70 to 3.25 kΩ
      a1-1 - a1-2 15°C (59°F) 2.14 to 2.58 kΩ
      a1-1 - a1-2 20°C (68°F) 1.71 to 2.05 kΩ
      a1-1 - a1-2 25°C (77°F) 1.38 to 1.64 kΩ
      a1-1 - a1-2 30°C (86°F) 1.11 to 1.32 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).

      Text in Illustration
      *a

      Component without harness connected

      (Evaporator Temperature Sensor (No. 1 Cooler Thermistor))
      *b Sensing Portion
      *c Resistance (kΩ)
      *d Allowable Range
      *e Temperature (°C (°F))
    NG

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

    OK

  3. INSPECT AIR CONDITIONING HARNESS ASSEMBLY

    1. Remove the air conditioning harness assembly Click here.

      A011TVCE22

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

      A011THAE49
      Standard Resistance
      Tester Connection Condition Specified Condition
      z1-6 (TEA) - a1-2 Always Below 1 Ω
      z1-5 (SGA) - a1-1 Always Below 1 Ω
      z1-6 (TEA) - Body ground Always 10 kΩ or higher
      z1-5 (SGA) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)
      *b

      Front view of wire harness connector

      (to Evaporator Temperature Sensor (No. 1 Cooler Thermistor))
    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here