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

DESCRIPTION

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WIRING DIAGRAM


  1. w/o Heated Windshield Defroster System

    B005NB7E13

  2. w/ Heated Windshield Defroster System

    B005L69E05
    B005PT6E05

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 steering wheel heater unit has a malfunction, replace the steering wheel assembly.

PROCEDURE


  1. CHECK IG1-MAIN RELAY


    1. Remove the IG1-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. B005LTYC03
      *1 IG1-MAIN Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Voltage is not applied between terminals 1 and 2 10 kΩ or higher
      Voltage is applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE IG1-MAIN RELAY

    OK

  2. CHECK HARNESS AND CONNECTOR (IG1-MAIN RELAY POWER SOURCE)


    1. Remove the IG1-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 (IG1-MAIN relay) - Body ground Always 11 to 14 V
      1 (IG1-MAIN relay) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (IG1-MAIN relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY) POWER SOURCE)


    1. Disconnect the J84 steering heater switch (integration control and panel assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      J84-4 (IG1) - Body ground Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the J84 steering heater switch (integration control and panel assembly) connector.

    2. B005OEZC02
      *a

      Component without harness connected

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

      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) Condition Specified Condition
      J84-4 (IG1) - J84-9 (IND) Always Below 1.25 V
      J84-16 (ECU) - J84-9 (IND) Steering heater switch (integration control and panel assembly) is pushed Below 1.25 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J84-4 (IG1) - J84-16 (ECU) Steering heater switch (integration control and panel assembly) is pushed Below 1 Ω
      Steering heater switch (integration control and panel assembly) 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

  5. CHECK HARNESS AND CONNECTOR (IG1-MAIN RELAY - SPIRAL CABLE SUB-ASSEMBLY)


    1. Remove the IG1-MAIN relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (IG1-MAIN Relay) - J23-4 (BHT) Always Below 1 Ω
      3 (IG1-MAIN Relay) or J23-4 (BHT) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (w/o Heated Windshield Defroster System) A
      OK (w/ Heated Windshield Defroster System) B
      NG C

    B

    CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY) - AIR CONDITIONING AMPLIFIER ASSEMBLY) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

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


    1. Disconnect the J84 steering heater switch (integration control and panel assembly) connector.

    2. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J84-9 (IND) - J23-1 (BTM) Always Below 1 Ω
      J84-16 (ECU) - J23-3 (ETM) Always Below 1 Ω
      J84-9 (IND) or J23-1 (BTM) - Body ground Always 10 kΩ or higher
      J84-16 (ECU) or J23-3 (ETM) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT SPIRAL CABLE SUB-ASSEMBLY


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

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

    2. Disconnect the J23 and z11 spiral cable sub-assembly connectors.

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

      B005PNQC10
      *a

      Component without harness connected

      (Spiral Cable Sub-assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      z11-2 (BTM) - J23-1 (BTM) Always 3 Ω or less
      z11-3 (ETM) - J23-3 (ETM) Always 3 Ω or less
      z11-1 (EHT) - J23-2 (EHT) Always Below 0.1 Ω
      z11-4 (BHT) - J23-4 (BHT) Always Below 0.1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    OK

  8. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY BODY GROUND)


    1. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J23-2 (EHT) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE STEERING WHEEL ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. CHECK HARNESS AND CONNECTOR (STEERING HEATER SWITCH (INTEGRATION CONTROL AND PANEL ASSEMBLY) - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the J84 steering heater switch (integration control and panel assembly) connector.

    2. Disconnect the J42 and J43 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J84-9 (IND) - J43-19 (IND-) Always Below 1 Ω
      J84-16 (ECU) - J42-26 (SW1) Always Below 1 Ω
      J84-9 (IND) or J43-19 (IND-) - Body ground Always 10 kΩ or higher
      J84-16 (ECU) or J42-26 (SW1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - SPIRAL CABLE SUB-ASSEMBLY)


    1. Disconnect the J43 and J48 air conditioning amplifier assembly connector.

    2. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J43-10 (SHIN) - J23-1 (BTM) Always Below 1 Ω
      J48-23 (HTR1) - J23-3 (ETM) Always Below 1 Ω
      J43-10 (SHIN) or J23-1 (BTM) - Body ground Always 10 kΩ or higher
      J48-23 (HTR1) or J23-3 (ETM) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT SPIRAL CABLE SUB-ASSEMBLY


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

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

    2. Disconnect the J23 and z11 spiral cable sub-assembly connectors.

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

      B005PNQC14
      *a

      Component without harness connected

      (Spiral Cable Sub-assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      z11-2 (BTM) - J23-1 (BTM) Always 3 Ω or less
      z11-3 (ETM) - J23-3 (ETM) Always 3 Ω or less
      z11-1 (EHT) - J23-2 (EHT) Always Below 0.1 Ω
      z11-4 (BHT) - J23-4 (BHT) Always Below 0.1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (SPIRAL CABLE SUB-ASSEMBLY BODY GROUND)


    1. Disconnect the J23 spiral cable sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      J23-2 (EHT) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


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

      Tech Tips

      Perform the inspection from the harness side with the connectors connected.

      B005QG6C01
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      		 - -
      Standard Voltage
      Tester Connection Condition Specified Condition
      J43-10 (SHIN) - Body ground Steering heater switch (integration control and panel assembly) is pushed Below 3 V
      J48-23 (HTR1) - Body ground Steering heater switch (integration control and panel assembly) is pushed 11 to 14 V for 0.08 seconds after heater switch (integration control and panel assembly) is turned on then below 1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE STEERING WHEEL ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY