DTC B2782-15: Power Source Control System Circuit Short to Battery or Open [11/2021 - 03/2023]: Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2025 Lexus NX 350, 2025 Lexus NX 250, 2024 Lexus NX 350, 2024 Lexus NX 250, and 2023 Lexus NX 350. However, it is still accessible from the selected car via links, so may be relevant.

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 with ECU assembly) is determined to be abnormal.

HINT:

The steering lock ECU (steering lock actuator with ECU assembly) is not connected to the CAN communication system. However, the steering lock ECU (steering lock actuator with ECU 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 Item	DTC Detection Condition	Trouble Area	DTC Output from	Priority	Note
B2782-15	Power Source Control System Circuit Short to Battery or Open	Either of the following conditions is met (1-trip detection logic (Only output while a malfunction is present and the ignition switch is ON.)): 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 with ECU assembly) Certification ECU (smart key ECU assembly) Wire harness or connector	Smart Access	A	DTC Output Confirmation Operation: Perform a steering lock/unlock operation. (The steering locks when a door is opened with the shift position in P and the ignition switch off. The steering unlocks when the ignition switch is turned to ACC or ON while carrying the key.)

VEHICLE CONDITION AND FAIL-SAFE FUNCTION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected	Fail-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 start).

RELATED DATA LIST AND ACTIVE TEST ITEMS

DTC No.	Data List and Active Test
B2782-15	-