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

DTC Code DTC Name
B1413/13 Evaporator Temperature Sensor Circuit

DESCRIPTION

The NO.1 cooler thermistor (Evaporator temperature sensor) is installed on the evaporator in the air conditioning 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. The signals change in accordance with the resistance of the NO.1 cooler thermistor (Evaporator temperature sensor). 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 NO.1 cooler thermistor (Evaporator temperature sensor) and reads voltage changes as changes in the resistance of the NO.1 cooler thermistor (Evaporator temperature sensor). This sensor is used for frost prevention.

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

  • NO.1 cooler thermistor (Evaporator temperature sensor)

  • Air conditioning harness

  • Air conditioning amplifier

WIRING DIAGRAM

A017BWME03

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (EVAP FIN TEMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the intelligent tester main switch on.

    3. Select the item below in the Data List, and read the value displayed on the intelligent tester.

      Data List / Air Conditioner:
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Evap Fin Temp

      Evaporator temperature sensor /

      Min.: -29.7°C (-21.46°F)

      Max.: 59.55°C (139.19°F)

      		 Actual evaporator temperature is displayed

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

      Short circuit: 59.55°C (139.19°F)
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      NG A
      OK (Checking from PROBLEM SYMPTOMS TABLE) B
      OK (Checking from DTC) C

    B

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    A

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


    1. Remove the No. 1 cooler thermistor.

      A017ENUE01

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

      Note


      • Touching the thermistor even slightly may change the resistance value. Be sure to hold the connector of the thermistor.

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

      Tech Tips

      As the temperature increases, the resistance decreases (see the graph).


    NG

    REPLACE NO. 1 COOLER THERMISTOR

    OK

  3. INSPECT AIR CONDITIONING HARNESS


    1. Remove the air conditioning harness.

    2. A017B5LE16

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

      Standard resistance
      Tester Connection Condition Specified Condition
      z17-6 (TE) - 2 Always Below 1 Ω
      z17-5 (SG) - 1 Always Below 1 Ω
      z17-6 (TE) - Body ground Always 10 kΩ or higher
      z17-5 (SG) - Body ground Always 10 kΩ or higher

    NG

    REPLACE AIR CONDITIONING HARNESS

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here