AIR CONDITIONING SYSTEM (for Automatic Air Conditioning System), Diagnostic DTC:B1419/19

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

DESCRIPTION

The rear room temperature sensor LH*1 or RH*2 (for driver side) 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 rear room temperature for the LH*1 or 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 rear room temperature sensor LH*1 or RH*2 and reads voltage changes as changes in the resistance of the rear room temperature sensor LH*1 or RH*2.

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

  • Rear room temperature sensor RH*2

  • Harness or connector between rear room temperature sensor LH and air conditioning amplifier assembly*1

  • Harness or connector between rear room temperature sensor RH and air conditioning amplifier assembly*2

  • Air conditioning amplifier assembly

Tech Tips

*1: for LHD

*2: for RHD

WIRING DIAGRAM

A0157WFE40
A0157WFE41

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER (AIR CONDITIONER)


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

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

      Rear room temperature sensor for LH*1 or 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

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

      Short in the circuit: 57.25°C (135.05°F).

      Tech Tips

      *1: for LHD

      *2: for RHD

      OK
      The display is as specified in the normal condition.

    NG
    OK
  2. INSPECT REAR ROOM TEMPERATURE SENSOR

    A0157GME03

    1. for LHD


      1. Remove the rear room temperature sensor LH Click here.

    2. for RHD


      1. Remove the rear room temperature sensor RH Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (+) - 2 (-) 10°C (50°F) 3.00 to 3.73 kΩ
      15°C (59°F) 2.45 to 2.88 kΩ
      20°C (68°F) 1.95 to 2.30 kΩ
      25°C (77°F) 1.60 to 1.80 kΩ
      30°C (86°F) 1.28 to 1.47 kΩ
      35°C (95°F) 1.00 to 1.22 kΩ
      40°C (104°F) 0.80 to 1.00 kΩ
      45°C (113°F) 0.65 to 0.85 kΩ
      50°C (122°F) 0.50 to 0.70 kΩ
      55°C (131°F) 0.44 to 0.60 kΩ
      60°C (140°F) 0.36 to 0.50 kΩ

      Note

      Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.

      Tech Tips

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

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

    B
    C
    A
  3. CHECK HARNESS AND CONNECTOR (REAR ROOM TEMPERATURE SENSOR - AIR CONDITIONING AMPLIFIER)

    A015CS0E09

    1. for LHD


      1. Disconnect the z55 sensor connector.

      2. Disconnect the E35 amplifier connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        z55-1 (+) - E35-18 (TR) Always Below 1 Ω
        z55-2 (-) - E35-2 (SG-6)
        E35-18 (TR) - Body ground Always 10 kΩ or higher
        E35-2 (SG-6) - Body ground
    2. A015CS0E10

      for RHD


      1. Disconnect the z56 sensor connector.

      2. Disconnect the E35 amplifier connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        z56-2 (-) - E35-2 (SG-6) Always Below 1 Ω
        z56-1 (+) - E35-19 (TR7)
        E35-2 (SG-6) - Body ground Always 10 kΩ or higher
        E35-19 (TR7) - Body ground

    NG
    OK