AIR CONDITIONING SYSTEM, Diagnostic DTC:B1419/19

DTC Code DTC Name
B1419/19 Rear Room Temperature Sensor Circuit

DESCRIPTION


The cooler thermistor (rear room temperature sensor LH*1 or RH*2) is installed in the rear quarter trim board LH*1 or RH*2 to detect the rear room temperature and control the heater and air conditioner "auto" mode. The resistance of the rear room temperature sensor LH*1 or RH*2 changes in accordance with the cooler thermistor (rear room temperature sensor LH*1or RH*2) seat. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies a voltage (5 V) to the cooler thermistor (rear room temperature sensor LH*1 or RH*2) and reads voltage changes as changes in the resistance of the cooler thermistor (rear room temperature sensor LH* or RH*2)

DTC Code DTC Detection Condition Trouble Area
B1419/19 An open or short in the cooler thermistor (rear room temperature sensor LH*1 or RH*2) circuit.

  • Cooler thermistor (rear room temperature sensor LH)*1

  • Cooler thermistor (rear room temperature sensor RH)*2

  • Harness or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM


  1. for LHD:

    B00196FE83
    *a Cooler Thermistor (Rear Room Temperature Sensor LH)
    *b Air Conditioning Amplifier Assembly

  2. for RHD:

    B00196FE84
    *a TSET
    *b Cooler Thermistor (Rear Room Temperature Sensor RH)
    *c Air Conditioning Amplifier Assembly

PROCEDURE


  1. READ VALUE USING GTS (ROOM TEMP SENSOR [REAR])


    • *1: for LHD

    • *2: for RHD


    1. Use the Data List to check if the rear room temperature sensor LH*1 or RH*2 is functioning properly Click here.

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Room Temp Sensor (Rear) Cooler thermistor (rear room temperature sensor for LH*1,RH*2) / Min.: -6.5°C (20.3°F), Max.: 57.25°C (135.05°F) Actual rear room temperature for LH*1 or RH*2 displayed

      Cooler thermistor (rear room temperature sensor for LH*1 or RH*2) system malfunction:


      • Open in the circuit: -6.5°C (20.3°F)

      • Short in the circuit: 57.25°C (135.05°F)
      OK
      The display is as specified in the normal condition.
      Result
      Result Proceed to
      OK (When troubleshooting according to the DTC) A
      OK (When troubleshooting according to Problem Symptoms Table) B
      NG C

    A

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    B

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

    C

  2. INSPECT COOLER THERMISTOR (REAR ROOM TEMPERATURE SENSOR)


    1. for LHD:


      1. Remove the cooler thermistor (rear room temperature sensor LH) Click here.

    2. for RHD


      1. Remove the cooler thermistor (rear room temperature sensor RH) Click here.

    3. Inspect the cooler thermistor (rear room temperature sensor) Click here.

      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    B

    REPLACE COOLER THERMISTOR (REAR ROOM TEMPERATURE SENSOR LH) Click here

    C

    REPLACE COOLER THERMISTOR (REAR ROOM TEMPERATURE SENSOR RH) Click here

    A

  3. CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR [REAR ROOMTEMPERATURE SENSOR] - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. for LHD:


      1. Disconnect the z38 cooler thermistor (rear room temperature sensor LH) connector.

      2. Disconnect the E35 air conditioning amplifier assembly connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        z38-1 - E35-21 (TR) Always Below 1 Ω
        z38-2 - E35-33 (SG) Always Below 1 Ω
        z38-1 - z38-2 Always 10 kΩ or higher
        z38-1 or E35-21 (TR) - Body ground Always 10 kΩ or higher
        z38-2 or E35-33 (SG) - Body ground Always 10 kΩ or higher

    2. for RHD:


      1. Disconnect the z37 cooler thermistor (rear room temperature sensor RH) connector.

      2. Disconnect the E35 air conditioning amplifier assembly connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        z37-1 - E35-22 (TEST) Always Below 1 Ω
        z37-2 - E35-33 (SG) Always Below 1 Ω
        z37-1 - z37-2 Always 10 kΩ or higher
        z37-1 or E35-22 (TEST) - Body ground Always 10 kΩ or higher
        z37-2 or E35-33 (SG) - Body ground Always 10 kΩ or higher

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR