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STEERING LOCK SYSTEM Unable to Unlock Steering Wheel (Hybrid Control System cannot Start)

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DTC Code DTC Name
  Unable to Unlock Steering Wheel (Hybrid Control System cannot Start)
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DESCRIPTION

The steering lock actuator assembly activates the steering lock motor and moves the lock bar into the steering column to lock the steering.

The steering may not unlock when the lock bar gets stuck in the lock hole of the steering column. In this case, if the power switch is turned on (READY) while shaking the steering wheel, as is done for a vehicle with a mechanical key, the lock bar will be unlocked. If the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the hybrid control system cannot be started.

Table 1. Related Data List and Active Test Items
Problem Symptom Data List Item Active Test Item
Unable to unlock steering wheel (hybrid control system)
  • Entry&Start

  • Unlock Request Receive

  • S Code Check

  • L Code Check

 -
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

  • When using the GTS with the power switch off, connect the GTS to the vehicle and turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the GTS and the vehicle begins. Then select the Model Code "KEY REGIST" under manual mode and enter the following menus: Body Electrical / Entry&Start(CAN). While using the GTS, periodically turn a courtesy light switch on and off at intervals of 1.5 seconds or less to maintain communication between the GTS and the vehicle.

  • Perform either of the following operations to lock/unlock the steering:


    • To unlock the steering, carry the key and turn the power switch on (ACC) or on (IG) .

    • To lock the steering, turn the power switch off with the shift lever in P, and then open a door.

  • The steering lock system uses LIN communication. First perform the inspections in "How to Proceed with Troubleshooting" to confirm that there are no communication malfunctions before proceeding with troubleshooting.

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  • After performing repairs, confirm that the problem does not recur.

  • Make sure that no DTCs are output. If any DTCs are output, proceed to the Diagnostic Trouble Code Chart.

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

  • When replacing the steering lock ECU (steering lock actuator assembly), certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU), registration must be performed (refer to Service Bulletin).

  • When disconnecting the cable from the negative (-) auxiliary battery terminal, some systems need to be initialized after the cable is reconnected.

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  • If the steering lock ECU (steering lock actuator assembly) or certification ECU (smart key ECU assembly) is replaced, be sure to confirm that the steering is unlocked by turning the steering wheel to the left and right before starting the hybrid control system. This function prevents the hybrid control system from starting while the steering is locked. If the steering is locked for any reason, open and close a door with the power switch off, and then unlock the steering by pressing the power switch.

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PROCEDURE


  1. Click here

    CHECK POWER SWITCH (SWITCH CONDITION)


    1. Check the power source mode change.


      1. When the key is inside the vehicle and the shift lever is in P, check that pressing the power switch with the brake pedal released causes the power source mode to change as follows:

        OK
        Off → On (ACC) → On (IG) → Off
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      GO TO ENTRY AND START SYSTEM (for Start Function) (PROBLEM SYMPTOMS TABLE)Click here

  2. Click here

    CHECK INDICATOR


    1. With the power switch on (IG), check that Steering Lock active is displayed on the multi-information display in the combination meter assembly.

      Result
      Result Proceed to
      Steering Lock active is displayed. A
      Steering Lock active is not displayed. B

  3. Click here

    CHECK STEERING UNLOCK


    1. While turning the steering wheel left and right, press the power switch.

    2. Check that the steering is unlocked.

      Result
      Result Proceed to
      The steering is unlocked. A
      The steering is not unlocked. B

  4. Click here

    CHECK FOR DTC


    1. Using the GTS, check if the certification ECU (smart key ECU assembly) DTCs are output.


      1. Body Electrical > Entry&Start > Trouble Codes


      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    • AClick here
    • B

      REPAIR CIRCUIT INDICATED BY OUTPUT CODE

  5. Click here

    READ VALUE USING GTS (UNLOCK REQUEST RECEIVE)


    1. Use the Data List to check if the steering lock request is functioning properly.


      1. Body Electrical > Entry&Start > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        Unlock Request Receive

        Reception state of steering unlock request signal by certification ECU (smart key ECU assembly) sent to ID code box (immobiliser code ECU)

        Tip:

        • The reception state is maintained for 10 seconds.

        • When 10 seconds or more have elapsed after receiving the signal, the item changes to "NG".

        		 OK or NG

        OK: Within 10 seconds of turning power switch on (IG) or on (ACC) or starting hybrid control system

        NG: Except above

        • If the unlock signal has not been received, the hybrid control system cannot be started.

        • If this item does not change to "OK" even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.



      1. Body Electrical > Entry&Start > Data List
        Tester Display
        Unlock Request Receive




      OK
      Within 10 seconds of turning the power switch on (ACC) or on (IG) or starting the hybrid control system, the Data List item changes to "OK".
      Result
      Proceed to
      OK
      NG

  6. Click here

    CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Disconnect the K28 steering lock ECU (steering lock actuator assembly) connector.

    2. A0021T0C38
      *a

      Front view of wire harness connector

      (to Steering Lock ECU (Steering Lock Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K28-1 (GND) - Body ground Always Below 1 Ω
      Note:

      If the result is not as specified, check for looseness in the ground cable connection.

      Standard Voltage
      Tester Connection Condition Specified Condition
      K28-7 (B) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. Click here

    INSPECT STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)


    1. Reconnect the K28 steering lock ECU (steering lock actuator assembly) connector.

    2. A0021EQC26
      *a

      Component with harness connected

      (Steering Lock ECU (Steering Lock Actuator Assembly))
      *b Steering Lock Motor not Operating
      *c Steering Lock Motor Operating

      Check the signal waveform according to the condition(s) in the table below.

      Standard Frequency
      Item Content
      Tester Connection K28-3 (IGE) - K28-1 (GND)
      Tool Setting 2 V/DIV., 200 ms./DIV.
      Vehicle Condition Steering lock motor not operating → Operating → Not operating
      Tip:

      • When taking measurements when the lock motor is stopped, it is not necessary to perform any operations.

      • In order to take measurements when the lock motor is operating, perform either of the following operations:


        • To unlock the steering, carry the key and turn the power switch on (ACC) or on (IG).

        • To lock the steering, turn the power switch off with the shift lever in P, and then open a door.

      Result
      Proceed to
      OK
      NG

  8. Click here

    CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY))


    1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

    2. Disconnect the K28 steering lock ECU (steering lock actuator assembly) connector.

    3. Disconnect the K137 certification ECU (smart key ECU assembly) connector.

    4. Check for deformation and corrosion of the connector case and terminals.

      OK
      There is no deformation or corrosion of the connector case or terminals.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K28-3 (IGE) - K137-24 (SLR+) Always Below 1 Ω
      K28-3 (IGE) - Body ground Always 10 kΩ or higher
      K137-24 (SLR+) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. Click here

    READ VALUE USING GTS (S CODE CHECK)


    1. Use the Data List to check if S code certification is functioning properly.


      1. Body Electrical > Entry&Start > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        S Code Check Verification result between certification ECU (smart key ECU assembly) and ID code box (immobiliser code ECU) OK or NG

        OK: Verification result normal

        NG: Verification result abnormal

        When a malfunction is present:


        • The ID code for the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is not registered or the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.

        • The steering cannot be locked.

        • The steering cannot be unlocked (the hybrid control system cannot be started).



      1. Body Electrical > Entry&Start > Data List
        Tester Display
        S Code Check




      OK
      OK is displayed on the GTS.
      Tip:

      Reasons for verification failure:


      • The certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.

      • There is a problem with the communication between ECUs.

      • An ECU is replaced, but is not registered.

      • An ECU is replaced with an ECU which has a code already stored in it.

      Result
      Proceed to
      OK
      NG

  10. Click here

    READ VALUE USING GTS (L CODE CHECK)


    1. Use the Data List to check if L code certification is functioning properly.


      1. Body Electrical > Entry&Start > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        L Code Check Verification result between ID code box (immobiliser code ECU) and steering lock ECU (steering lock actuator assembly) OK or NG

        OK: Verification result normal

        NG: Verification result abnormal

        When a malfunction is present:


        • The ID code for the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is not registered or the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is malfunctioning.

        • The steering cannot be locked.

        • The steering cannot be unlocked (the hybrid control system cannot be started).



      1. Body Electrical > Entry&Start > Data List
        Tester Display
        L Code Check




      OK
      OK is displayed on the GTS.
      Tip:

      Reasons for verification failure:


      • The steering lock ECU (steering lock actuator assembly) or ID code box (immobiliser code ECU) is malfunctioning.

      • There is a problem with the communication between ECUs.

      • An ECU is replaced, but is not registered.

      • An ECU is replaced with an ECU which has a code already stored in it.

      Result
      Proceed to
      OK
      NG

  11. Click here

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)


    1. Replace the steering lock ECU (steering lock actuator assembly) with a new one.

      Click here

    2. Perform registration (refer to Service Bulletin).

    3. Turn the power switch on (IG).

    4. Turn the steering wheel and check the steering condition.

      OK
      Steering is unlocked.
      Result
      Proceed to
      OK
      NG

    • OK

      END

    • NG

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

  12. Click here

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.

    2. Perform registration (refer to Service Bulletin).

    3. Use the Data List to check if L code certification is functioning properly.


      1. Body Electrical > Entry&Start > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        L Code Check Verification result between ID code box (immobiliser code ECU) and steering lock ECU (steering lock actuator assembly) OK or NG

        OK: Verification result normal

        NG: Verification result abnormal

        When a malfunction is present:


        • The ID code for the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is not registered or the ID code box (immobiliser code ECU) or steering lock ECU (steering lock actuator assembly) is malfunctioning.

        • The steering cannot be locked.

        • The steering cannot be unlocked (the hybrid control system cannot be started).



      1. Body Electrical > Entry&Start > Data List
        Tester Display
        L Code Check




      OK
      OK is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    • OK

      END

    • NG

      REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)Click here

  13. Click here

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)


    1. Replace the ID code box (immobiliser code ECU) with a new one.

    2. Perform registration (refer to Service Bulletin).

    3. Use the Data List to check if S code certification is functioning properly.


      1. Body Electrical > Entry&Start > Data List
        Tester Display Measurement Item Range Normal Condition Diagnostic Note
        S Code Check Verification result between certification ECU (smart key ECU assembly) and ID code box (immobiliser code ECU) OK or NG

        OK: Verification result normal

        NG: Verification result abnormal

        When a malfunction is present:


        • The ID code for the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is not registered or the certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU) is malfunctioning.

        • The steering cannot be locked.

        • The steering cannot be unlocked (the hybrid control system cannot be started).



      1. Body Electrical > Entry&Start > Data List
        Tester Display
        S Code Check




      OK
      OK is displayed on the GTS.
      Result
      Proceed to
      OK
      NG

    • OK

      END

    • NG

      REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)