AIR CONDITIONING SYSTEM, Diagnostic DTC:B1419/19

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

DESCRIPTION

The rear room temperature sensor is installed in the rear panel. It detects the rear cabin temperature to control the air conditioning AUTO mode. The resistance of the rear room temperature sensor changes in accordance with the rear cabin temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The A/C amplifier applies a voltage (5 V) to the rear room temperature sensor and reads voltage changes as changes in the resistance of the rear room temperature sensor.

DTC No. DTC Detection Condition Trouble Area
B1419/19 Open or short in rear room temperature sensor circuit

  • Rear room temperature sensor

  • Harness or connector between rear room temperature sensor and A/C amplifier

  • A/C amplifier

WIRING DIAGRAM

A01CD78E14

INSPECTION PROCEDURE

PROCEDURE


  1. READ VALUE USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the intelligent tester on.

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

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

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

      Rear room temperature sensor /

      Min.: -6.5°C (20.3°F)

      Max.: 57.25°C (135.05°F)

      		 Actual rear cabin temperature displayed -
      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 here

    C

    REPLACE A/C AMPLIFIER Click here

    A

  2. INSPECT REAR ROOM TEMPERATURE SENSOR


    1. Remove the rear room temperature sensor.

    2. A01CFYJE01

      Disconnect the rear room temperature sensor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z20-1 - z20-2 10°C (50°F) 3.00 to 3.73 kΩ
      z20-1 - z20-2 15°C (59°F) 2.45 to 2.88 kΩ
      z20-1 - z20-2 20°C (68°F) 1.95 to 2.30 kΩ
      z20-1 - z20-2 25°C (77°F) 1.60 to 1.80 kΩ
      z20-1 - z20-2 30°C (86°F) 1.28 to 1.47 kΩ
      z20-1 - z20-2 35°C (95°F) 1.00 to 1.22 kΩ
      z20-1 - z20-2 40°C (104°F) 0.80 to 1.00 kΩ
      z20-1 - z20-2 45°C (113°F) 0.65 to 0.85 kΩ
      z20-1 - z20-2 50°C (122°F) 0.50 to 0.70 kΩ
      z20-1 - z20-2 55°C (131°F) 0.44 to 0.60 kΩ
      z20-1 - z20-2 60°C (140°F) 0.36 to 0.50 kΩ

      Note


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

      • 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).


    NG

    REPLACE REAR ROOM TEMPERATURE SENSOR Click here

    OK

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


    1. A01CBOZE27

      Disconnect the A/C amplifier connector.

    2. A01CAJPE20

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z20-1 - G34-17 (TR) Always Below 1 Ω
      z20-2 - G34-7 (SG-6) Always Below 1 Ω
      z20-1 - Body ground Always 10 kΩ or higher
      z20-2 - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE A/C AMPLIFIER Click here