STEERING LOCK SYSTEM Unable to Unlock Steering Wheel (Engine cannot Start)

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 engine switch is turned on (IG) while shaking the steering wheel, in the same manner as is done for a vehicle with a mechanical key, the lock bar will be unlocked. If the certification ECU (smart key ECU assembly), ID code box (immobiliser code ECU) or ECM is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the engine cannot be started.

Related Data List and Active Test Items
Problem Symptom Data List Item Active Test Item
Unable to unlock steering wheel (Engine cannot start)
-

WIRING DIAGRAM

A01G5HEE01

INSPECTION PROCEDURE

Note


  • When using the GTS with the vehicle engine 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 engine switch on (ACC) or on (IG) with the shift lever in P.

    • To lock the steering, turn the engine 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 Click here.

  • 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 Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection 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 (-) battery terminal, some systems need to be initialized after the cable is reconnected Click here.

  • If the steering lock ECU (steering lock actuator 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 engine. This function prevents the engine from starting while the steering is locked. If the steering is locked for any reason, open and close a door with the engine switch off, and then unlock the steering by pressing the engine switch.

PROCEDURE


  1. CHECK DTC (ALL)


    1. Using the GTS, confirm the output of DTCs for all systems.

      OK
      No DTCs are output.

      Note


      • When using the GTS with the vehicle engine 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.

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


    NG

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

    OK

  2. CHECK ENGINE 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 engine switch with the brake pedal released causes the power source mode to change as follows:

        OK
        Off → On (ACC) → On (IG) → Off

    NG

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

    OK

  3. READ VALUE USING GTS (UNLOCK REQUEST RECEIVE)


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

      Entry&Start
      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) and sent to ID code box (immobiliser code ECU) / OK or NG

      Tech Tips


      • 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: Within 10 seconds of turning engine switch on (IG) or on (ACC) or starting engine

      NG: Except above

      • If the unlock signal has not been received, the engine 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.
      OK
      Within 10 seconds of turning the engine switch on (ACC) or on (IG) or starting the engine, the Data List item changes to "OK".

    B

    Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. Disconnect the H18 steering lock ECU connector.

    2. A01G6Q5E62
      Text in Illustration
      *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
      H18-1 (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
      H18-7 (B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT STEERING LOCK ECU (MOTOR ACTIVATION COMMAND SIGNAL)


    1. Reconnect the H18 steering lock ECU connector.

    2. A01G9D2E12
      Text in Illustration
      *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 H18-3 (IGE) - H18-1 (GND)
      Tool Setting 2 V/DIV., 200 ms./DIV.
      Vehicle Condition Steering lock motor not operating → Steering lock motor operating → Steering lock motor not operating

      Tech Tips


      • 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 engine switch on (ACC) or on (IG) with the shift lever in P.

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


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here

  6. READ VALUE USING GTS (S CODE CHECK)


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

      Entry&Start
      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 engine cannot be started).
      OK
      OK is displayed on the GTS.

      Tech Tips

      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.


    NG

    Click here

    OK

  7. READ VALUE USING GTS (L CODE CHECK)


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

      Entry&Start
      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 / 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 is not registered or the ID code box (immobiliser code ECU) or steering lock ECU is malfunctioning.

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).
      OK
      OK is displayed on the GTS.

      Tech Tips

      Reasons for verification failure:


      • The steering lock ECU 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.


    NG

    Click here

    OK

  8. REPLACE 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 engine switch on (IG).

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

      OK
      Steering is unlocked.

    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    OK

    END

  9. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)


    1. Replace the certification ECU (smart key ECU assembly) 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.

      Entry&Start
      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 engine cannot be started).
      OK
      OK is displayed on the GTS.

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

    OK

    END

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

      Entry&Start
      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 / 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 is not registered or the ID code box (immobiliser code ECU) or steering lock ECU is malfunctioning.

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).
      OK
      OK is displayed on the GTS.

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

    OK

    END