STEERING LOCK SYSTEM Unable to Unlock Steering Wheel (Hybrid Control System 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 hybrid control system 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) or power management control ECU is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the hybrid control system cannot be started.

Related Data List and Active Test Items
Problem Symptom	Data List Item	Active Test Item
Unable to unlock steering wheel (Hybrid control system cannot start)	Smart Key All items Click here	-

WIRING DIAGRAM

INSPECTION PROCEDURE

Note

When using the Techstream with the power switch off, perform either of the following: 1) Turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and vehicle begins, or 2) connect the Techstream to the vehicle, select the vehicle type under manual mode, and then enter the following menus: Body Electrical / Smart Key / Trouble Codes.
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) with the shift lever in P.
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 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) or certification ECU (smart key ECU assembly), registration must be performed Click here.
When disconnecting the cable from the negative (-) auxiliary battery terminal, some systems need to be initialized after the cable is reconnected Click here.
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. 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. This prevents the hybrid control system from starting while the steering is locked.

PROCEDURE

CHECK DTC (ALL)
1. Using the Techstream, confirm the output of DTCs for all systems.
  
  OK
  
  No DTCs are output.
  Note
  - When using the Techstream with the power switch off, perform either of the following: 1) Turn a courtesy light switch on and off at intervals of 1.5 seconds or less until communication between the Techstream and vehicle begins, or 2) connect the Techstream to the vehicle, select the vehicle type under manual mode, and then enter the following menus: Body Electrical / Smart Key / Trouble Codes.
  - 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
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
NG
GO TO SMART KEY SYSTEM (for Start Function) (PROBLEM SYMPTOMS TABLE) Click here

OK

OK
No DTCs are output.

OK
Off → on (ACC) → on (IG) → off

READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE)

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

Smart Key
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) / 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 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.

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".

Click here

CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

Disconnect the I24 steering lock ECU connector.

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

Standard Resistance

Tester Connection	Condition	Specified Condition
I24-1 (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
I24-7 (B) - Body ground	Always	11 to 14 V

Text in Illustration
*a	Front view of wire harness connector (to Steering Lock ECU (Steering Lock Actuator Assembly))

REPAIR OR REPLACE HARNESS OR CONNECTOR

INSPECT STEERING LOCK ECU (MOTOR ACTIVATION COMMAND SIGNAL)

Reconnect the I24 steering lock ECU connector.

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

Standard Frequency
Item	Content
Tester Connection	I24-3 (IGE) - I24-1 (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

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

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 power switch on (ACC) or on (IG) with the shift lever in P.
To lock the steering, turn the power switch off with the shift lever in P, and then open a door.

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here

READ VALUE USING TECHSTREAM (L CODE CHECK)

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

Smart Key
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 / 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 steering lock ECU is not registered or the certification ECU (smart key ECU assembly) or steering lock ECU is malfunctioning. The steering cannot be locked. The steering cannot be unlocked (the hybrid control system cannot be started).

OK
OK is displayed on the Techstream.

Tech Tips

Reasons for verification failure:

The steering lock ECU 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.

Click here

REPLACE STEERING LOCK ACTUATOR ASSEMBLY
1. Replace the steering lock ECU (steering lock actuator assembly) with a new one Click here.
2. Perform the registration procedures Click here.
3. Turn the power switch on (IG).
4. Operate the steering wheel and check the steering condition.
  
  OK
  
  Steering is unlocked.
NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Click here

OK

END

OK
Steering is unlocked.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

Replace the certification ECU (smart key ECU assembly) with a new one Click here.
Perform the registration procedures Click here.

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

Smart Key
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 / 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 steering lock ECU is not registered or the certification ECU (smart key ECU assembly) or steering lock ECU is malfunctioning. The steering cannot be locked. The steering cannot be unlocked (the hybrid control system cannot be started).

OK
OK is displayed on the Techstream.

REPLACE STEERING LOCK ACTUATOR ASSEMBLY Click here

END