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 conditioning unit to detect the temperature of the cooled air that has passed through the evaporator and control the air conditioning. It sends appropriate 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 Code DTC Detection Condition Trouble Area
B1413 An open or short in the No. 1 cooler thermistor circuit.

  • No. 1 cooler thermistor

  • Harness or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A003F25E50

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING GTS (NO. 1 COOLER THERMISTOR)


    1. Use the Data List to check if the No. 1 cooler thermistor is functioning properly Click here.

      Air Conditioner
      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

      Open in the circuit: -29.7°C (-21.46°F).

      Short in the circuit: 59.55°C (139.19°F).
      OK
      The display is as specified in the normal condition column.
      Result
      Result Proceed to
      OK (When troubleshooting according to problem symptoms table) A
      OK (When troubleshooting according to the DTC) B
      NG C

    B

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    C

    INSPECT NO. 1 COOLER THERMISTOR Click here

    A

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

  2. INSPECT NO. 1 COOLER THERMISTOR


    1. Remove the No. 1 cooler thermistor.

    2. Inspect the No. 1 cooler thermistor Click here.


    NG

    REPLACE NO. 1 COOLER THERMISTOR

    OK

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


    1. Disconnect the H18 air conditioning harness assembly connector.

    2. Disconnect the H8 No. 1 cooler thermistor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H18-24 (TP) - H8-1 Always Below 1 Ω
      H18-31 (SG) - H8-2 Always Below 1 Ω
      H18-24 (TP) - Body ground Always 10 kΩ or higher
      H18-31 (SG-1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here