AIR CONDITIONING SYSTEM, Diagnostic DTC:B14A8

DTC Code DTC Name
B14A8 Glass Temperature Sensor Circuit

DESCRIPTION

The air conditioner thermistor assembly is installed to the glass window and detects the temperature of the glass window for use in the heater and air conditioner "AUTO" operation. The resistance of the air conditioner thermistor assembly changes according to changes in the temperature of the glass window. When the temperature of the glass window decreases, the resistance increases, and when the temperature of the glass window increases, the resistance decreases. The air conditioning amplifier assembly supplies voltage (5 V) to the air conditioner thermistor assembly and monitors the changes in voltage that result from the changes in the resistance of the air conditioner thermistor assembly.

The glass temperature sensor is integrated with the air conditioning thermistor assembly.

DTC Code DTC Detection Condition Trouble Area
B14A8 Open or short in glass temperature sensor circuit

  • Air conditioning thermistor assembly

  • Harness or connector

  • Air conditioning amplifier assembly

WIRING DIAGRAM

A01FQMRE05

INSPECTION PROCEDURE

Note


  • This DTC is stored when there is malfunction in the sensor ground circuit, when DTC B14A8, B14A9 and B14AA are output simultaneously, perform troubleshooting for DTC B14AA first.

  • The whole air conditioning thermistor assembly should be replaced if the glass temperature sensor is malfunctioning.

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

  • Before disconnecting the cable form the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter Click here.

PROCEDURE


  1. READ VALUE USING GTS (GLASS TEMPERATURE)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

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

      Air Conditioner
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      Glass Temperature

      Glass temperature/

      Min.: -327.68°C (-557.82°F)

      Max.: 327.67°C (621.81°F)

      		 Actual glass 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 AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

  2. INSPECT AIR CONDITIONING THERMISTOR ASSEMBLY


    1. Remove the air conditioning thermistor assembly Click here.

    2. Inspect the air conditioning thermistor assembly Click here.


    NG

    REPLACE AIR CONDITIONING THERMISTOR ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - AIR CONDITIONING THERMISTOR ASSEMBLY)


    1. Disconnect the N157 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Y6-4 (TFG) - N157-22 (TFG) Always Below 1 Ω
      Y6-1 (SEG3) - N157-33 (SG-5) Always Below 1 Ω
      Y6-4 (TFG) - Body ground Always 10 kΩ or higher
      Y6-1 (SEG3) - Body ground Always 10 kΩ or higher
      Y6-4 (TFG) - Y6-1 (SEG3) Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here