AIR CONDITIONING SYSTEM, Diagnostic DTC:B1417/17

DTC Code DTC Name
B1417/17 Rear Evaporator Temperature Sensor Circuit

DESCRIPTION

The No. 2 cooler thermistor (rear evaporator temperature sensor) is installed on the evaporator in the rear cooler unit to detect the cooled air temperature that has passed through the evaporator and control the air conditioning. It sends appropriate signals to the rear junction block ECU and the air conditioning amplifier via the CAN communication line. The resistance of the No. 2 cooler thermistor (rear evaporator temperature sensor) changes in accordance with the cooled air temperature that has passed through the rear evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier applies voltage (5 V) to the No. 2 cooler thermistor (rear evaporator temperature sensor) and reads voltage changes as the resistance of the No. 2 cooler thermistor (rear evaporator temperature sensor) changes. This sensor is used for frost prevention.

Tech Tips

This circuit uses the CAN communication line. Before performing the inspection, check that the CAN communication system is functioning normally.

DTC Code DTC Detection Condition Trouble Area
B1417/17 Open or short in rear evaporator temperature sensor circuit

  • No. 2 cooler thermistor (rear evaporator temperature sensor)

  • Harness or connector between rear air conditioning harness and rear junction block ECU

  • Rear air conditioning harness (rear evaporator temperature sensor)

  • Rear junction block ECU

  • Air conditioning amplifier

  • CAN communication line

WIRING DIAGRAM

A01H1L0E03

INSPECTION PROCEDURE

PROCEDURE


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


    1. Use the Data List to check if the evaporator fin thermistor is functioning properly.

      Air Conditioner
      Tester Display Measurement Item / Range Normal Condition Diagnostic Note
      Ambient Temp Sens (Rear)

      Rear evaporator temperature sensor /

      Min.: -29.7°C (-21.46°F)

      Max.: 59.55°C (139.19°F)

      		 Actual rear evaporator temperature is displayed

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

      Short in circuit: 59.55°C (139.19°F)
      OK
      The display is as specified in the normal condition.

    NG

    INSPECT NO. 2 COOLER THERMISTOR (REAR EVAPORATOR TEMPERATURE SENSOR) Click here

    OK

    REPLACE AIR CONDITIONING AMPLIFIER Click here

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

    A01GX1ME19

    1. Remove the No. 2 cooler thermistor (rear evaporator temperature sensor).


    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).

      Result
      Result Proceed to
      OK A
      NG (w/ Rear Air Conditioning System) B
      NG (w/o Rear Air Conditioning System) C

    B

    REPLACE NO. 2 COOLER THERMISTOR (REAR EVAPORATOR TEMPERATURE SENSOR) Click here

    C

    REPLACE NO. 2 COOLER THERMISTOR (REAR EVAPORATOR TEMPERATURE SENSOR) Click here

    A

  3. CHECK HARNESS AND CONNECTOR (REAR AIR CONDITIONING HARNESS - REAR JUNCTION BLOCK ECU)

    A01GYWPE02

    1. Disconnect the S90 rear air conditioning harness connector.

    2. Disconnect the S62 and LA rear junction block ECU connectors.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      S90-3 (TE) - S62-25 (RRTE) Always Below 1 Ω
      S90-4 (SG) - LA-51 (SSRE)
      S62-25 (RRTE) - Body ground Always 10 kΩ or higher
      LA-51 (SSRE) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE REAR AIR CONDITIONING HARNESS


    1. Replace the rear air conditioning harness Click here.

      Tech Tips

      Since the rear air conditioning harness cannot be inspected while it is removed from the vehicle, replace the rear air conditioning harness with a normal one.


    NEXT

  5. CHECK DTC


    1. Clear the DTCs Click here.

    2. Check for DTCs Click here.

      OK
      DTC B1417 is not output.

    NG

    REPLACE REAR JUNCTION BLOCK ECU

    OK

    END (REAR AIR CONDITIONING HARNESS IS DEFECTIVE)