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) (w/ ID Code Box) or ECM is replaced, the system needs to be initialized and registered. 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)	Entry&Start All items Click here	-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

Note

When using the GTS with the engine 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 GTS and vehicle begins, or 2) connect the GTS to the vehicle and select "Manual" from the initial screen on the GTS. Select "Key Code Registration" under model code.
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).
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 completing 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.
Before replacing the certification ECU (smart key ECU assembly), steering lock actuator assembly (steering lock ECU) or ID code box (immobiliser code ECU) (w/ ID Code Box), 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 actuator assembly (steering lock ECU) 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.

*: for Automatic Transmission

PROCEDURE

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, 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 GTS and vehicle begins, or 2) connect the GTS to the vehicle and select "Manual" from the initial screen on the GTS. Select "Key Code Registration" under model code.
  - 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 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*1, check that pressing the engine switch with the brake pedal*1 or clutch pedal*2 released causes the power source mode to change as follows:
    - *1: for Automatic Transmission
    - *2: for Manual Transmission
    OK
    
    Off → on (ACC) → on (IG) → off
NG
GO TO ENTRY AND START 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 GTS (UNLOCK REQUEST RECEIVE)

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*1	Reception state of steering unlock command signal determined 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.
Unlock Request Receive*2	Reception state of steering unlock command signal determined 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 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.

*1: w/ ID Code Box
*2: w/o ID Code Box

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".

Result

Result	Proceed to
OK	A
NG (w/o ID Code Box)	B
NG (w/ ID Code Box)	C

READ VALUE USING GTS (L CODE CHECK) Click here

READ VALUE USING GTS (S CODE CHECK) Click here

CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)

Disconnect the D59 steering lock actuator assembly (steering lock ECU) connector.

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

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

Standard Resistance

Tester Connection	Condition	Specified Condition
D59-1 (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
D59-7 (B) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) (MOTOR ACTIVATION COMMAND SIGNAL)

Reconnect the D59 steering lock actuator assembly (steering lock ECU) connector.

Text in Illustration
*a	Component with harness connected (Steering Lock Actuator Assembly (Steering Lock ECU))
*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	D59-3 (SLR+) - D59-1 (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).
To lock the steering, turn the engine switch off with the shift lever is in P*, and then open a door.

*: for Automatic Transmission

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

READ VALUE USING GTS (L CODE CHECK)

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 certification ECU (smart key ECU assembly) and 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 certification ECU (smart key ECU assembly) or steering lock actuator assembly (steering lock ECU) is not registered or the certification ECU (smart key ECU assembly) or steering lock actuator assembly (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 actuator assembly (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.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Click here

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)
1. Replace the steering lock actuator assembly (steering lock ECU) 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.
OK
END

NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK
Steering is unlocked.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

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 certification ECU (smart key ECU assembly) and 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 certification ECU (smart key ECU assembly) or steering lock actuator assembly (steering lock ECU) is not registered or the certification ECU (smart key ECU assembly) or steering lock actuator assembly (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.

END

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

READ VALUE USING GTS (S CODE CHECK)

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

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Click here

READ VALUE USING GTS (L CODE CHECK)

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

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

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)
1. Replace the steering lock actuator assembly (steering lock ECU) 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.
OK
END

NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

OK
Steering is unlocked.

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

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

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 a malfunction is present: The ID code for the ID code box (immobiliser code ECU) or certification ECU (smart key ECU assembly) is not registered or the ID code box (immobiliser code ECU) or certification ECU (smart key ECU 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.

END

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)

REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)

Replace the steering lock actuator assembly (steering lock ECU) with a new one Click here.
Perform registration (refer to Service Bulletin).

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

END

REPLACE ID CODE BOX (IMMOBILISER CODE ECU)