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Steering Lock System (Diagnostic Codes & Symptom Tests): Overview Lexus IS III

Steering Column 5 illustrations ~587 words

DESCRIPTION

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

HINT

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).

DTC No.Detection ItemDTC Detection ConditionTrouble AreaNote
B2788IG2 Signal MalfunctionMismatch between the steering lock ECU (steering lock actuator assembly) IG2 input from the LIN communication system and from the direct line (1-trip detection logic (Only output while a malfunction is present and the engine switch is on (IG).)).IGN No. 2 fuse Steering lock ECU (Steering lock actuator assembly) Harness or connectorDTC Output Confirmation Operation: No confirmation operation is necessary (monitoring is continuous).
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

DTC No.Data List ItemActive Test Item
B2788

RELATED DATA LIST AND ACTIVE TEST ITEMS

Scheme 71

Scheme 71: WIRING DIAGRAM

The certification ECU (smart key ECU assembly) 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 certification ECU (smart key ECU assembly) to the steering lock ECU (steering lock actuator assembly) is determined to be abnormal.

HINT

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).

DTC No.Detection ItemDTC Detection ConditionTrouble AreaNote
B2782Power Source Control ECU MalfunctionEither of the following conditions is met (1-trip detection logic (Only output while a malfunction is present and the engine switch is on (IG).)): 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 ECU (Steering lock actuator assembly) Certification ECU (Smart key ECU assembly) Harness or connectorDTC Output Confirmation Operation: Perform 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.)
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

DTC No.Data List ItemActive Test Item
B2782Smart Access Power Supply Short

RELATED DATA LIST AND ACTIVE TEST ITEMS

Scheme 72

Scheme 72: WIRING DIAGRAM

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

The steering lock ECU (steering lock actuator assembly) detects whether the steering lock is in the lock or unlock position by using the lock sensor and unlock sensor of the steering lock motor.

The steering lock ECU (steering lock actuator assembly) receives lock and unlock request signals from the certification ECU (smart key ECU assembly) and responds with lock and unlock operation signals.

HINT

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).

DTC No.Detection ItemDTC Detection ConditionTrouble AreaNote
B2781Open / Short in Steering Lock ECUOne of the following conditions is met (1-trip detection logic (Only output while a malfunction is present and the engine switch is on (IG).)): The steering lock sensor or unlock sensor is malfunctioning (When both detection switches turn on, the system is determined to be malfunctioning.). The steering lock motor activation circuit has a short circuit. The steering lock motor activation circuit has an open circuit.Steering lock ECU (Steering lock actuator assembly) LIN communication systemDTC Output Confirmation Operation: No confirmation operation is necessary (monitoring is continuous).

Scheme 73

Scheme 73
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

DTC No.Data List ItemActive Test Item
B2781Smart Access Sensor Value Motor Driver Short

RELATED DATA LIST AND ACTIVE TEST ITEMS

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

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, as is done for a vehicle with a mechanical key, to change the position of the lock hole.

Problem SymptomData List ItemActive Test Item
Steering Lock does not LockSmart Access Lock Request Receive S Code Check L Code Check Main Body FL Door Courtesy SW

RELATED DATA LIST AND ACTIVE TEST ITEMS

Scheme 74

Scheme 74: WIRING DIAGRAM

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 the engine switch is turned on (IG) while shaking the steering wheel, 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 (immobilizer code ECU) or ECM is replaced, the system needs to be initialized. Otherwise, the steering cannot be unlocked and the engine cannot be started.

Problem SymptomData List ItemActive Test Item
Unable to unlock steering wheel (Engine cannot start)Smart Access Unlock Request Receive S Code Check L Code Check

RELATED DATA LIST AND ACTIVE TEST ITEMS

Scheme 75

Scheme 75: WIRING DIAGRAM