AIR CONDITIONING SYSTEM, Diagnostic DTC:B1419/19

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

DESCRIPTION

The cooler thermistor (No. 2 room temperature sensor) is installed in the deck trim side panel to detect the cabin temperature which is used to control the heater and air conditioning system AUTO mode. The resistance of the cooler thermistor (No. 2 room temperature sensor) changes in accordance with the cabin temperature. 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 (No. 2 room temperature sensor) and reads voltage changes due to changes in the resistance of the cooler thermistor (No. 2 room temperature sensor).

DTC No. Detection Item DTC Detection Condition Trouble Area Memory Note
B1419/19 Rear Room Temperature Sensor Circuit Open or short in cooler thermistor (No. 2 room temperature sensor) circuit

  • Cooler thermistor (No. 2 room temperature sensor)

  • Harness or connector

  • Air conditioning amplifier assembly

 Memorized (4 seconds or more) -

Tech Tips

The air conditioning amplifier assembly stores the DTC of the respective malfunction if it has occurred for the period of time indicated in the parentheses.

WIRING DIAGRAM

B006MEGE20
*a Cooler Thermistor (No. 2 Room Temperature Sensor)
*b Air Conditioning Amplifier Assembly

CAUTION / NOTICE / HINT

Note

When the battery is disconnected or the air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.

Click here

PROCEDURE


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


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

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


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Room Temp Sensor (Rear) Cooler thermistor (No. 2 room temperature sensor)

      Min.: -6.50°C (-20.30°F)

      Max.: 57.25°C (135.05°F)

      		 Actual ambient temperature displayed

      Cooler thermistor (No. 2 room temperature sensor) system malfunction:


      • When open circuit: -6.50°C (-20.30°F)

      • When short circuit: 57.25°C (135.05°F)

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Room Temp Sensor (Rear)
      OK
      The display is as specified in the normal condition column.
      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 for LHD: Click here for RHD: Click here

    B

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

    C

  2. INSPECT COOLER THERMISTOR (NO. 2 ROOM TEMPERATURE SENSOR)


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

      Click here

    2. Inspect the cooler thermistor (No. 2 room temperature sensor).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  3. CHECK HARNESS AND CONNECTOR (COOLER THERMISTOR [NO. 2 ROOM TEMPERATURE SENSOR] - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the e1 cooler thermistor (No. 2 room temperature sensor) connector.

    2. Disconnect the G38 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
      e1-1 - G38-7 (SG-6) Always Below 1 Ω
      e1-2 - G38-20 (TR) Always Below 1 Ω
      e1-1 - e1-2 Always 10 kΩ or higher
      e1-1 or G38-7 (SG-6) - Body ground Always 10 kΩ or higher
      e1-2 or G38-20 (TR) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY for LHD: Click here for RHD: Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR