HEATED STEERING WHEEL SYSTEM Steering Wheel does not Heat Up When Heated Steering Wheel Switch is Pressed

DESCRIPTION

The heater unit heats the steering wheel when the combination switch is operated.

Tech Tips


  • The heater unit is built into the steering wheel.


  • As the steering wheel cannot be disassembled, replace the steering wheel when there is a malfunction in the heater unit.

WIRING DIAGRAM

A01ER9SE03

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK COMBINATION SWITCH ASSEMBLY (LED OPERATION)

    A01EPG9

    1. Check the illumination condition of the LED.

      Result
      LED Condition Proceed to
      Blinks

      Engine switch on (IG)

      Combination switch is pushed and held continuously for 10 seconds or more

      		 A
      Illuminates

      Engine switch on (IG)

      Combination switch is pushed

      		 B
      Does not blink or illuminate

      Engine switch on (IG)

      Combination switch is pushed

      		 B

    B

    INSPECT STEERING WHEEL ASSEMBLY (HEATER·THERMOSTAT) Click here

    A

  2. INSPECT STEERING WHEEL ASSEMBLY (THERMISTOR)


    1. Disconnect the steering wheel controller connector.

    2. A01EMXQE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Heated Steering Wheel Controller)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (TH2) - 3 (TH1) 25°C (77°F) 9.7 to 10.3 kΩ

    NG

    REPLACE HEATED STEERING WHEEL CONTROLLER Click here

    OK

  3. INSPECT STEERING WHEEL ASSEMBLY (HEATER·THERMOSTAT)


    1. Disconnect the steering wheel controller connector.

    2. A01EMXQE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Heated Steering Wheel Controller)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (SH2) - 4 (SH1) 20°C (68°F) 1.88 to 2.26 Ω

    NG

    REPLACE HEATED STEERING WHEEL CONTROLLER Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH - SPIRAL CABLE)


    1. Disconnect the E100 combination switch connector.

    2. Disconnect the E101 spiral cable connector.

    3. A01EQ21E02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Combination switch)
      *b

      Front view of wire harness connector

      (to Spiral Cable)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E100-1 (+) - E101-1 (BTM) Always Below 1 Ω
      E100-11 (IN) - E101-3 (ETM) Always Below 1 Ω
      E101-2 (EHT) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E101-4 (BHT) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR

    OK

  5. INSPECT SPIRAL CABLE SUB-ASSEMBLY

    Note

    If there are any defects as mentioned below, replace the spiral cable with a new one:

    Scratches, cracks, dents or chips in the connector or spiral cable.


    1. Disconnect the E101 spiral cable connector.

    2. Disconnect the heated steering wheel controller connector.

    3. A01EQYQE05
      Text in Illustration
      *a

      Component without harness connected

      (Spiral Cable)
      *b

      Front view of harness connector

      (to Heated Steering Wheel Controller)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (CCU) - E101-1 (BTM) Always Below 1 Ω
      2 (CCV) - E101-3 (ETM) Always Below 1 Ω
      3 (CCX) - E101-2 (EHT) Always Below 1 Ω
      4 (CCW) - E101-4 (BHT) Always Below 1 Ω

    NG

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    OK

  6. CHECK COMBINATION SWITCH ASSEMBLY


    1. Disconnect the combination switch connector.

    2. A01EO24E02
      Text in Illustration
      *a

      Component without harness connected

      (to Combination switch)

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

      Tech Tips

      As the circuit has a diode, perform the measurement in diode test mode and make sure that the polarity is correct.

      Standard Voltage

      Tester Connection

      Positive (+) tester probe - Negative (-) tester probe

      		 Switch Condition Specified Condition
      E100-9 (IG) - E100-11 (IN) Combination switch is pushed Below 1.25 V

    NG

    REPLACE COMBINATION SWITCH ASSEMBLY Click here

    OK

    REPLACE HEATED STEERING WHEEL CONTROLLER Click here