Lexus NX: System Description
SYSTEM DESCRIPTION
UNLOCK OPERATION CONDITIONS FOR STEERING LOCK
(a) When the following condition is met, the unlock operation is performed.
- The power switch is on (ACC) or on (IG).
HINT:
When the power switch is turned on (ACC) or on (IG) and the key and certification ECU (smart key ECU assembly) are verified, the steering is unlocked.
(b) When any of the following conditions are met, key verification is performed.
- The power switch is pressed.
- The brake pedal is depressed so that the hybrid control system can be started.
- 30 seconds have elapsed after opening and closing a door.
HINT:
- Key verification occurs when the code emitted from the key and the code stored by the certification ECU (smart key ECU assembly) are compared to check that they match.
- Certification ECU (smart key ECU assembly) verification occurs when the S code and L code are verified while the hybrid control system is being started or the power switch is being pushed. The ID code box (immobiliser code ECU) uses the S code to determine whether the certification ECU (smart key ECU assembly) is authorized. The steering lock ECU (steering lock actuator assembly) uses the L code to determine whether the ID code box (immobiliser code ECU) is authorized.
LOCK OPERATION CONDITIONS FOR STEERING LOCK
(a) When all of the following conditions are met and the certification ECU (smart key ECU assembly) has been verified, the lock operation is performed.
- The power switch is off.
- The shift lever is in P.
- A door is opened or a door lock operation (door lock, wireless door lock or key-linked lock operation*) is performed.
HINT:
*: This is the lock/unlock operation with the mechanical key.
WARNING FUNCTION
(a) A check smart access system with push-button start message is displayed on the multi-information display in the combination meter assembly when one of the following occurs: 1) A vehicle speed signal malfunction is detected, 2) a malfunction that interferes with steering lock ECU (steering lock actuator assembly) operation is detected.
If a malfunction occurs which results in the message being displayed, the hybrid control system cannot be started once it is turned off.
HINT:
DTCs are stored in all cases listed above.
STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) DESCRIPTION
(a) The steering lock ECU and steering lock motor are built into the steering lock actuator assembly of the steering column assembly.
(b) The steering lock ECU (steering lock actuator assembly) is not connected to the CAN communication system. However, the steering lock ECU (steering lock actuator assembly) is connected to the certification ECU (smart key ECU assembly) via LIN communication and communicates with other components via CAN communication through the certification ECU (smart key ECU assembly).
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How To Proceed With Troubleshooting
CAUTION / NOTICE / HINT HINT:
Use the following procedures to troubleshoot the steering lock system.
*: Use the Techstream.
PROCEDURE 1. VEHICLE BROUGHT TO WORKSHOP
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Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT:
Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of
Terminals Of Ecu
TERMINALS OF ECU TERMINAL INSPECTION *a Component without harness connected (Steering Lock ECU (Steering Lock Actuator Assembly)) - - (a) Measure the voltage and resistance according to t
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Fail-safe Chart
FAIL-SAFE CHART If a problem occurs in the power steering system, the power steering assist will be stopped or the amount of power assist will be decreased to protect the system. Power Steering System Malfunction Fail-safe Operation Power steering warning light Buzzer
Torque sensor (
