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

DESCRIPTION

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WIRING DIAGRAM

B002F1YE01

CAUTION / NOTICE / HINT

Tech Tips


  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • The steering wheel heater unit is built into the steering wheel assembly which cannot be disassembled. Therefore, when the steering wheel heater unit has a malfunction, replace the steering wheel assembly.

PROCEDURE


  1. INSPECT STEERING WHEEL HEATER UNIT (THERMISTOR/HEATER/THERMOSTAT)


    1. B002DRKC10
      *a Component without harness connected (Steering Wheel Heater Control Assembly)

      Disconnect the B steering wheel heater control assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B-1 (TH1) - B-2 (TH2) 10 to 30°C (50 to 86°F) 8.132 to 18.43 kΩ
      B-4 (SH1) - B-3 (SH2) 20°C (68°F) 1.89 to 2.25 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE STEERING WHEEL ASSEMBLY Click here

    OK

  2. INSPECT SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY


    1. Check the connectors and cables of the spiral cable with sensor sub-assembly.

      OK
      There are no defects such as scratches, cracks, dents or damage on the connectors or cables.

    2. Disconnect the K27 and z5 spiral cable with sensor sub-assembly connectors.

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

      B002CHBC16
      *a

      Component without harness connected

      (Spiral Cable with Sensor Sub-assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      z5-1 (BTM) - K27-1 (BTM) Always 3 Ω or less
      z5-2 (ETM) - K27-3 (ETM) Always 3 Ω or less
      z5-3 (EHT) - K27-2 (EHT) Always 0.02 to 0.28 Ω
      z5-4 (BHT) - K27-4 (BHT) Always 0.02 to 0.28 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY Click here

    OK

  3. CHECK STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY)


    1. B002E2PC07
      *a

      Component without harness connected

      (Steering Heater Switch (Integration Control and Panel Assembly)

      Disconnect the steering heater switch (integration control and panel assembly) connector.

    2. 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 do not mistake the polarity.

      Standard Voltage
      Tester Connection (Positive (+) tester probe - Negative (-) tester probe) Switch Condition Specified Condition
      K5-1 (B) - K5-10 (+) Always Below 1.25 V
      K5-9 (IN) - K5-10 (+) Steering heater switch is pushed Below 1.25 V

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      K5-1 (B) - K5-9 (IN) Steering heater switch is pushed Below 200 Ω
      K5-1 (B) - K5-9 (IN) Steering heater switch is not pushed 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY) - SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY)


    1. Disconnect the K5 steering heater switch (integration control and panel assembly) connector.

    2. Disconnect the K27 spiral cable with sensor sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K5-10 (+) - K27-1 (BTM) Always Below 1 Ω
      K5-9 (IN) - K27-3 (ETM) Always Below 1 Ω
      K5-10 (+) or K27-1 (BTM) - Body ground Always 10 kΩ or higher
      K5-9 (IN) or K27-3 (ETM) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (IG CIRCUIT)


    1. Disconnect the K5 steering heater switch (integration control and panel assembly) connector.

    2. B002CBLC01
      *a

      Front view of wire harness connector

      (to Steering Heater Switch (Integration Control and Panel Assembly))

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      K5-1 (B) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (+B CIRCUIT)


    1. Disconnect the K27 spiral cable with sensor sub-assembly connector.

    2. B002DEAC01
      *a

      Front view of wire harness connector

      (to Spiral Cable with Sensor Sub-assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K27-4 (BHT) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY BODY GROUND)


    1. Disconnect the K27 spiral cable with sensor sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K27-2 (EHT) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE STEERING WHEEL HEATER CONTROL ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR