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 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) or ECM is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the engine cannot be started.

WIRING DIAGRAM

INSPECTION PROCEDURE

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.

   
   

   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 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 elapse 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".

   
   

   NG

   Click here

   OK

4. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

   
   

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

      

      Text in Illustration

      *a

      Component with harness connected (Certification ECU (Smart Key ECU Assembly))

      -

      -

      Standard Voltage
      Tester Connection Condition Specified Condition N93-25 (P) - A34-11 (E) Shift lever in P 9 V or higher Shift lever not in P 1.5 V or less

   
   

   NG

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

   OK

5. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

   
   

   1. Disconnect the steering lock ECU connector.

   2. 

      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 N24-1 (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 N24-7 (B) - Body ground Always 11 to 14 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

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

   
   

   1. Reconnect the steering lock ECU connector.

   2. 

      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	N24-3 (IGE) - N24-1 (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 ECU (STEERING LOCK ACTUATOR ASSEMBLY) Click here

7. 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 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).

      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

8. 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 (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 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 engine cannot be started).

      OK
      OK is displayed on the GTS.

      Tech Tips

      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.

   
   

   NG

   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.

   
   

   NG

   REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

   OK

   END

10. 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.

       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 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).

       OK
       OK is displayed on the GTS.

    
    

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

    OK

    END

11. 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.

       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 (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 engine cannot be started).

       OK
       OK is displayed on the GTS.

    
    

    NG

    REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

    OK

    END

12. CHECK HARNESS AND CONNECTOR (SHIFT LOCK CONTROL ECU (TRANSMISSION FLOOR SHIFT ASSEMBLY) - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY))

    
    

    1. Disconnect the N49 transmission floor shift assembly connector.

    2. Disconnect the N93 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 N49-3 (P2) - N93-25 (P) Always Below 1 Ω N49-3 (P2) - Body ground 10 kΩ or higher N93-25 (P) - Body ground

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

13. INSPECT SHIFT LOCK CONTROL ECU (TRANSMISSION FLOOR SHIFT ASSEMBLY)

    
    

    1. Reconnect the transmission floor shift assembly connector.

    2. 

       Text in Illustration

       *a	Component with harness connected (Shift lock Control ECU (transmission floor shift assembly))

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

       Standard Voltage
       Tester Connection Condition Specified Condition N49-3 (P2) - Body ground Shift lever in P 9 V or higher Shift lever not in P 1.5 V or less

       Result

       Result		Proceed to
       OK		A
       NG	for A760H	B
       	for AA81E	C
       	for A960E	D

    
    

    B

    GO TO SHIFT LEVER (INSPECTION) Click here

    C

    GO TO SHIFT LEVER (INSPECTION) Click here

    D

    GO TO SHIFT LEVER (INSPECTION) Click here

    A

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)