Unable to Unlock Steering Wheel (Engine cannot Start)
STEERING COLUMN: STEERING LOCK SYSTEM: Unable to Unlock Steering Wheel (Engine cannot Start)
- Unable to Unlock Steering Wheel (Engine cannot Start)
DESCRIPTION
The steering lock actuator activates the steering lock motor and moves the lock bar into the steering column to lock the steering wheel.
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 Engine Immobilizer System (w/ Smart Key System).
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* When using the Techstream 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 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 electrical key transmitter and turn the engine switch on (ACC) or on (IG) while the shift lever is in P (for Automatic Transaxle).
* To lock the steering, turn the engine switch off with the shift lever in P (for Automatic 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 LIN Communication System.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
* Make sure that no DTCs are output. If any DTCs are output, proceed to Diagnostic Trouble Code Chart Reading and Clearing Diagnostic Trouble Codes.
* When replacing the steering lock actuator assembly (steering lock ECU), certification ECU (smart key ECU assembly) or ID code box (immobiliser code ECU), registration must be performed Engine Immobilizer System (w/ Smart Key System).
* 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.
* After completing repairs, confirm that the problem does not reoccur.
* When disconnecting the cable from the negative (-) battery terminal, some systems need to be initialized after the cable is reconnected Repair Instruction - Initialization.
HINT
Related Data List and Active Test Items
PROCEDURE
1. CHECK DTC (ALL) Unable to Lock Steering Wheel
NG -- GO TO DTC CHART
OK -- Continue to next step.
2. CHECK ENGINE SWITCH (SWITCH CONDITION)
(a) Check the power source mode change.
(1) When the electrical key transmitter is inside the vehicle and the shift lever is in P (for Automatic Transaxle), check that pressing the engine switch with the brake pedal (for Automatic Transaxle) or clutch pedal (for Manual Transaxle) 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) Problem Symptoms Table
OK -- Continue to next step.
3. READ VALUE USING TECHSTREAM (UNLOCK REQUEST RECEIVE)
(a) Use the Data List to check if the steering lock command is functioning properly.
Smart Key
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 -- READ VALUE USING TECHSTREAM (S CODE CHECK)
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (STEERING LOCK ECU - BATTERY AND BODY GROUND)
(a) Disconnect the C18 steering lock ECU connector.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:
NOTICE:
If the result is not as specified, check for looseness in the connection which leads to ground.
Standard Voltage:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. INSPECT STEERING LOCK ECU
(a) Reconnect the C18 steering lock ECU connector.
(b) Check the signal waveform according to the condition(s) in the table below.
Measurement Conditions
HINT
* 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 electrical key transmitter and turn the engine switch on (ACC) or on (IG) while the shift lever is in P*.
* To lock the steering, turn the engine switch off with the shift lever in P*, and then open a door.
*: for Automatic Transaxle
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Disassembly
6. READ VALUE USING TECHSTREAM (S CODE CHECK) Unable to Lock Steering Wheel
NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)
OK -- Continue to next step.
7. READ VALUE USING TECHSTREAM (L CODE CHECK) Unable to Lock Steering Wheel
NG -- REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU)
OK -- Continue to next step.
8. REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Unable to Lock Steering Wheel
NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal
OK -- END
9. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Unable to Lock Steering Wheel
NG -- REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Removal
OK -- END
10. REPLACE STEERING LOCK ACTUATOR ASSEMBLY (STEERING LOCK ECU) Unable to Lock Steering Wheel
NG -- REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Removal
OK -- END