AIR CONDITIONING SYSTEM, Diagnostic DTC:B1462/62

DTC Code DTC Name
B1462/62 Room Humidity Sensor Circuit

DESCRIPTION

The air conditioning thermistor assembly (humidity sensor) detects cabin humidity. The voltage of the air conditioning thermistor assembly (humidity sensor) changes in accordance with cabin humidity. The air conditioning amplifier assembly reads changes in the air conditioning thermistor assembly (humidity sensor).

The humidity sensor is integrated with the air conditioning thermistor assembly.

DTC No. DTC Detecting Condition Trouble Area
B1462/62 Open or short in humidity sensor circuit

  • Air conditioning thermistor assembly (humidity sensor)

  • Harness or connector between air conditioning thermistor assembly (humidity sensor) and air conditioning amplifier assembly

  • Air conditioning amplifier assembly

Tech Tips

The whole air conditioning thermistor assembly should be replaced if the humidity sensor is malfunctioning.

WIRING DIAGRAM

A011WA4E01

INSPECTION PROCEDURE

PROCEDURE

  1. READ VALUE USING TECHSTREAM

    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

    4. Enter the following menus: Body Electrical / 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
      Humidity Sensor

      Humidity sensor /

      Min.: 0%, Max.: 100%

      		 Actual cabin humidity 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. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

    1. Disconnect the S3 air conditioning thermistor assembly (humidity sensor) connector.

      A011YO0E05

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      S3-5 (S5V) - Body ground Power switch on (IG) 4.5 to 5.5 V
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Air Conditioning Thermistor Assembly (Humidity Sensor))
    NG

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING THERMISTOR ASSEMBLY (HUMIDITY SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    OK

  3. INSPECT AIR CONDITIONING THERMISTOR ASSEMBLY (HUMIDITY SENSOR)

    1. Reconnect the S3 air conditioning thermistor assembly (humidity sensor) connector.

      A011XFZE06

    2. Turn the power switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      S3-3 (RH) - S3-1 (SEG3) Humidity is 5 to 15 % 1.01 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 15 to 25 % 1.37 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 25 to 35 % 1.73 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 35 to 45 % 2.09 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 45 to 55 % 2.45 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 55 to 65 % 2.81 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 65 to 75 % 3.17 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 75 to 85 % 3.53 V
      S3-3 (RH) - S3-1 (SEG3) Humidity is 85 to 95 % 3.89 V

      Note

      • Do not touch the room humidity sensor because it may be affected by body temperature and may not work properly.

      • Hold the sensor only by its connector.

      • The output voltage at an ambient temperature of 25°C (77°F) is shown above.

      Tech Tips

      As the humidity increases, the voltage increases (see the graph).

      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Thermistor Assembly (Humidity Sensor))
      *b Heat Conduction Sheet Part
      *c Voltage (V)
      *d Relative Humidity (%)
    NG

    REPLACE AIR CONDITIONING THERMISTOR ASSEMBLY (HUMIDITY SENSOR) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING THERMISTOR ASSEMBLY (HUMIDITY SENSOR) - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    1. Disconnect the I77 air conditioning amplifier assembly connector.

    2. Disconnect the S3 air conditioning thermistor assembly (humidity sensor) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      S3-5 (S5V) - I77-31 (S5-4) Always Below 1 Ω
      S3-3 (RH) - I77-28 (RH) Always Below 1 Ω
      S3-1 (SEG3) - I77-35 (SG-4) Always Below 1 Ω
      S3-5 (S5V) - Body ground Always 10 kΩ or higher
      S3-3 (RH) - Body ground Always 10 kΩ or higher
      S3-1 (SEG3) - Body ground Always 10 kΩ or higher
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here