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

DTC Code DTC Name
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 an engine start operation is performed 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) (w/ Multi-information Display (Dot Display Type)) or ECM is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the engine 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 (Engine cannot start)

-

WIRING DIAGRAM

C259297N02

CAUTION / NOTICE / HINT

Note:

  • When using the GTS with the engine switch off to troubleshoot:

    Connect the GTS to the DLC3 and turn a courtesy light switch on and off at 1.5 second intervals until communication between the GTS and vehicle begins.

  • 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 (except Mnual Tansaxle).

    • To lock the steering, turn the engine switch off with the shift lever in P (except Manual Transaxle), 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 occur.

  • 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) (w/ Multi-information Display (Dot Display Type)), registration must be performed (refer to Service Bulletin).

  • 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. 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. This prevents the engine from starting while the steering is locked.

  • When starting the engine, make sure that the shift lever is in P (except Manual Transaxle) and that the shift lever is not tilted.

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 engine switch off to troubleshoot:

        Connect the GTS to the DLC3 and turn a courtesy light switch on and off at 1.5 second intervals until communication between the GTS and vehicle begins.

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

    Result

    Proceed to

    OK

    NG
    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 (except Manual Transaxle) or N (for Manual Transaxle), 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

    Result

    Proceed to

    OK

    NG
    NG

    GO TO 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 command is functioning properly.

      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) and sent to ID code box (immobiliser code ECU)*1

      Reception state of steering unlock request signal by certification ECU (smart key ECU assembly)*2

      Tip:

      • The reception state is maintained for 10 seconds.

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

      OK or NG

      OK: Within 10 sec. of turning the engine switch on (IG) or on (ACC), or of an engine start operation being performed

      NG: Engine switch on (IG) or on (ACC), or engine start operation not performed

      • The engine cannot be started when an unlock request signal cannot be received.

      • If OK is not displayed even though the steering unlock conditions are met, the certification ECU (smart key ECU assembly) may be malfunctioning.

      • *1: w/ Multi-information Display (Dot Display Type)

      • *2: w/ Multi-information Display (Segment Display Type)

      Body Electrical > Entry&Start > Data List

      Tester Display

      Unlock Request Receive

      OK

      The certification ECU (smart key ECU assembly) receives a lock request signal within 10 seconds of turning the engine switch from on (IG) to off and opening a door with the shift lever in P (except Manual Transaxle), and OK is displayed on the GTS screen.

    Result

    Proceed to

    OK (except Manual Transaxle)

    OK (for Manual Transaxle)

    NG (w/ Multi-information Display (Dot Display Type))

    NG (w/ Multi-information Display (Segment Display Type))
    OK (for Manual Transaxle)

    CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)Click here

    NG (w/ Multi-information Display (Dot Display Type))

    READ VALUE USING GTS (S CODE CHECK)Click here

    NG (w/ Multi-information Display (Segment Display Type))

    READ VALUE USING GTS (L CODE CHECK)Click here

    OK (except Manual Transaxle)

  4. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

      B264896C36

      *a

      Component with harness connected

      (Certification ECU (Smart Key ECU Assembly))

      -

      -

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      G84-25 (P) - G82-11 (E)

      Shift lever in P

      9 V or higher

      Shift lever not in P

      1.5 V or less

    Result

    Proceed to

    OK

    NG
    NG

    CHECK HARNESS AND CONNECTOR (SHIFT LOCK CONTROL ECU (LOWER SHIFT LEVER ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

    1. C157850C27

      *a

      Front view of wire harness connector

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

      Disconnect the G5 steering lock ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G5-1 (GND) - Body ground

      Always

      Below 1 Ω
      Note:

      If the result is not as specified, check for looseness in the connection which leads to ground.

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      G5-7 (B) - Body ground

      Always

      11 to 14 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Reconnect the G5 steering lock ECU connector.

    2. C241547C17

      *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.

      Table 2. Standard Frequency

      Item

      Content

      Tester Connection

      G5-3 (IGE) - G5-1 (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
      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 engine switch on (ACC) or on (IG) with the shift lever in P (except manual transaxle).

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

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)

    Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. READ VALUE USING GTS (S CODE CHECK)

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

      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 NG is displayed:

      • 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).

      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
    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)Click here

    OK

  8. READ VALUE USING GTS (L CODE CHECK)

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

      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 NG is displayed:

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

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).

      Body Electrical > Entry&Start > Data List

      Tester Display

      L 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
    NG

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

    OK

  9. 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 procedures (Refer to the Service Bulletin).

    3. Turn the engine 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)

  10. CHECK HARNESS AND CONNECTOR (SHIFT LOCK CONTROL ECU (LOWER SHIFT LEVER ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

    1. Disconnect the G35 lower shift lever assembly connector.

    2. Disconnect the G84 certification ECU (smart key ECU assembly) connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G35-2 (P2) - G84-25 (P)

      Always

      Below 1 Ω

      G35-2 (P2) - Body ground

      10 kΩ or higher

      G84-25 (P) - Body ground

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. INSPECT SHIFT LOCK CONTROL ECU (LOWER SHIFT LEVER ASSEMBLY)

    1. Reconnect the G35 lower shift lever assembly connector.

    2. C197449C07

      *a

      Component with harness connected

      (Shift Lock Control ECU (Lower Shift Lever Assembly))

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      G35-2 (P2) - Body ground

      Shift lever in P

      9 V or higher

      Shift lever not in P

      1.5 V or less

      Result

      Proceed to

      OK

      NG (for U660F)

      NG (for U760E)

      NG (for U760F)

      NG (for K111)

      NG (for K111F)
    OK

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    NG (for U660F)

    GO TO SHIFT LEVER (INSPECTION)

    Click here

    NG (for U760E)

    GO TO SHIFT LEVER (INSPECTION)

    Click here

    NG (for U760F)

    GO TO SHIFT LEVER (INSPECTION)

    Click here

    NG (for K111)

    GO TO SHIFT LEVER (INSPECTION)

    Click here

    NG (for K111F)

    GO TO SHIFT LEVER (INSPECTION)

    Click here

  12. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    1. Replace the certification ECU (smart key ECU assembly) with a new one (Refer to the Service Bulletin).

    2. Perform registration procedures (Refer to the Service Bulletin).

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

      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 NG is displayed:

      • 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).

      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 ID CODE BOX (IMMOBILISER CODE ECU)

  13. 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 procedures (Refer to the Service Bulletin).

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

      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 NG is displayed:

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

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).

      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 ID CODE BOX (IMMOBILISER CODE ECU)

  14. READ VALUE USING GTS (L CODE CHECK)

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

      Body Electrical > Entry&Start > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      L Code Check

      Verification result between certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator assembly)

      OK or NG

      OK: Verification result normal

      NG: Verification result abnormal

      When NG is displayed:

      • The ID code for the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator assembly) is not registered or the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator assembly) is malfunctioning.

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).

      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 certification ECU (smart key ECU assembly) 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
    NG

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)Click here

    OK

  15. 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 engine 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)

  16. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

    1. Replace the certification ECU (smart key ECU assembly) with a new one (refer to Service Bulletin).

    2. Perform registration procedures (refer to Service Bulletin).

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

      Body Electrical > Entry&Start > Data List

      Tester Display

      Measurement Item

      Range

      Normal Condition

      Diagnostic Note

      L Code Check

      Verification result between certification ECU (smart key ECU assembly) and steering lock ECU (steering lock actuator assembly)

      OK or NG

      OK: Verification result normal

      NG: Verification result abnormal

      When NG is displayed:

      • The ID code for the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator assembly) is not registered or the certification ECU (smart key ECU assembly) or steering lock ECU (steering lock actuator assembly) is malfunctioning.

      • The steering cannot be locked.

      • The steering cannot be unlocked (the engine cannot be started).

      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