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

DTC Code DTC Name
B1413 Evaporator Temperature Sensor Circuit

DESCRIPTION

The 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, which is used to control the air conditioning system. It sends signals to the air conditioning amplifier assembly. The resistance of the No. 1 cooler thermistor changes in accordance with the temperature of the cooled air 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 No. 1 cooler thermistor and reads voltage changes as the resistance of the No. 1 cooler thermistor changes. This sensor is used for frost prevention.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Memory

B1413

Evaporator Temperature Sensor Circuit

Open or short in evaporator temperature sensor circuit

  • No. 1 cooler thermistor

  • Harness or connector between No. 1 cooler thermistor and air conditioning amplifier assembly

  • Air conditioning amplifier assembly

Memorized

(4 sec. or more)*1

  • *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

WIRING DIAGRAM

E236721E30

PROCEDURE

  1. READ VALUE USING GTS

    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Check the value(s) by referring to the table below.

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      Evaporator Fin Thermistor

      No. 1 cooler thermistor

      Min.: -29.7°C (21.46°F)

      Max.: 59.55°C (139.19°F)

      Actual evaporator temperature displayed

      -

      Body Electrical > Air Conditioner > Data List

      Tester Display

      Evaporator Fin Thermistor

      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 hereClick here

    C

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click hereClick hereClick here

    A

  2. INSPECT NO. 1 COOLER THERMISTOR

    1. Remove the No. 1 cooler thermistor.

      Click here

      E268737C01

      *a

      Component without harness connected

      (No. 1 Cooler Thermistor)

      *b

      Sensing Portion

      *c

      Resistance (kΩ)

      *d

      Temperature (°C (°F))

      *e

      Allowable Range

      -

      -

    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:

      • Hold the sensor only by its connector. Touching the sensing portion may change the resistance value.

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

      Tip:

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

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE NO. 1 COOLER THERMISTOR

    Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 COOLER THERMISTOR - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    1. Disconnect the E62 air conditioning amplifier assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      E62-15 (SG-3) - E67-2

      Always

      Below 1 Ω

      E62-4 (TE) - E67-1

      Always

      Below 1 Ω

      E62-15 (SG-3) - Body ground

      Always

      10 kΩ or higher

      E62-4 (TE)- Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click hereClick hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR