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

DESCRIPTION

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WIRING DIAGRAM

A000S9UE03

CAUTION / NOTICE / HINT

Tech Tips


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

  • The steering vibration and heater ECU and steering wheel heater unit is built into the steering wheel assembly. Therefore, when the steering vibration and heater ECU and/or steering wheel heater unit has a malfunction, replace the steering wheel assembly.

PROCEDURE


  1. INSPECT STEERING HEATER SWITCH


    1. Remove the steering heater switch Click here.

    2. Inspect the steering heater switch Click here.


    NG

    REPLACE STEERING HEATER SWITCH Click here

    OK

  2. INSPECT SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY


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

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

    2. Disconnect the N174 and z24 spiral with sensor cable sub-assembly connectors.

      A000N6GE02
      Text in Illustration
      *a

      Component without harness connected

      (Spiral with Sensor Cable Sub-assembly)

      		 - -

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      z24-1 - N174-2 (EHT) Always Below 1 Ω
      z24-2 - N174-1 (BTM) Always Below 1 Ω
      z24-3 - N174-3 (ETM) Always Below 1 Ω
      z24-4 - N174-4 (BHT) Always Below 1 Ω

    NG

    REPLACE SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (IG CIRCUIT)


    1. Disconnect the N6 steering heater switch connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N6-1 (B) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (IG CIRCUIT)


    1. Disconnect the N174 spiral with sensor cable sub-assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N174-4 (BHT) - Body ground Power switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH - SPIRAL WITH SENSOR CABLE SUB-ASSEMBLY)


    1. Disconnect the N6 steering heater switch connector.

    2. Disconnect the N174 spiral with sensor cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N6-10 (+) - N174-1 (BTM) Always Below 1 Ω
      N6-9 (IN) - N174-3 (ETM) Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the N174 spiral with sensor cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N174-2 (EHT) - Body ground Always Below 1 Ω

    OK

    REPLACE STEERING WHEEL ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR