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Steering Lock System (Diagnostic Codes & Symptom Tests): Overview Lexus GX J150

Steering Column 5 illustrations ~541 words

DESCRIPTION

The steering lock ECU and steering lock motor are built into the steering lock actuator assembly.

The steering lock ECU detects whether the steering lock is in the lock or unlock position by using the lock position sensor of the steering lock motor.

The steering lock ECU receives lock and unlock command signals from the certification ECU and responds with lock and unlock operation signals.

HINT

The steering lock ECU is not connected to the CAN communication system. However, the steering lock ECU is connected to the certification ECU via LIN communication and communicates with other components via CAN communication through the certification ECU.

DTC CodeDetection ConditionTrouble AreaDTC Output Confirmation Operation
B2781One of the following conditions is met (1-trip detection logic*1): The steering lock/unlock position sensor is malfunctioning*2. The steering lock motor activation circuit has a short circuit. The steering lock motor activation circuit has an open circuit.Steering lock actuator assembly (steering lock ECU) LIN communication systemNo confirmation operation is necessary (monitoring is continuous).
  1. *1: Only output while a malfunction is present and the engine switch is on (IG).
  2. *2: When both detection switches turn on, the system is determined to be malfunctioning.

Scheme 66

Scheme 66
Vehicle Condition when Malfunction DetectedFail-safe Function when Malfunction Detected
The steering cannot be locked or unlocked. For this reason, the engine cannot be started.Prohibits the engine from being started (the engine does not crank).

VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

The power management control ECU has a power source mode switching function.

This DTC is stored when the IGE input (the steering lock motor activation permission signal) sent directly from the power management control ECU to the steering lock ECU is determined to be abnormal.

HINT

The steering lock ECU is not connected to the CAN communication system. However, the steering lock ECU is connected to the certification ECU via LIN communication and communicates with other components via CAN communication through the certification ECU.

DTC CodeDetection ConditionTrouble AreaDTC Output Confirmation Operation
B2782Either condition is met (1-trip detection logic*): The steering lock motor activation command circuit has a short circuit. The steering lock motor activation command circuit has an open circuit. HINT: If the power supply signal from the LIN communication line does not match the power supply signal from the direct line, the system is determined to be malfunctioning.Steering lock actuator assembly (steering lock ECU) Power management control ECU Harness or connectorPerform a steering lock/unlock operation. (The steering locks when a door is opened with the shift lever in P and the engine switch off. The steering unlocks when the engine switch is turned on [ACC] or on [IG] while carrying the key.)
  1. *: Only output while a malfunction is present and the engine switch is on (IG).
Vehicle Condition when Malfunction DetectedFail-safe Function when Malfunction Detected
The steering cannot be locked or unlocked. For this reason, the engine cannot be started.Prohibits the engine from being started (the engine does not crank).

VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

Scheme 67

Scheme 67: WIRING DIAGRAM

This DTC is stored when the steering lock ECU detects an IG2 power supply malfunction.

HINT

The steering lock ECU is not connected to the CAN communication system. However, the steering lock ECU is connected to the certification ECU via LIN communication and communicates with other components via CAN communication through the certification ECU.

DTC CodeDetection ConditionTrouble AreaDTC Output Confirmation Operation
B2788Mismatch between the steering lock ECU IG2 input from the LIN communication system and from the direct line (1-trip detection logic*).IGN fuse Steering lock actuator assembly (steering lock ECU) Harness or connectorNo confirmation operation is necessary (monitoring is continuous).
  1. *: Only output while a malfunction is present and the engine switch is on (IG).
Vehicle Condition when Malfunction DetectedFail-safe Function when Malfunction Detected
The steering cannot be locked or unlocked. For this reason, the engine cannot be started.

VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

Scheme 68

Scheme 68: WIRING DIAGRAM

The steering lock actuator activates the steering lock motor and moves the lock bar into the steering column to lock the steering wheel.

When the steering lock is operating, the steering may not lock when the lock bar is not aligned with the lock hole of the steering column. In this case, the steering can be locked by turning the steering wheel a little in the same manner as is done for a vehicle with a mechanical key to change the position of the lock hole.

Scheme 69

Scheme 69: WIRING DIAGRAM

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, ID code box or ECM is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the engine cannot be started. Refer to REGISTRATION .

Scheme 70

Scheme 70: WIRING DIAGRAM