DTC B278D-96: ID-BOX Component Internal Failure [10/2022 - ]: Description

WARNING: This page is about a different car, the 2025 Lexus RX 350, 2024 Lexus RX 350, and 2023 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

When the certification ECU (smart key ECU assembly) detects an input signal indicating that the vehicle is equipped with an ID code box even though the ID code box is not registered, the certification ECU (smart key ECU assembly) stores this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	DTC Output from	Priority	Note
B278D-96	ID-BOX Component Internal Failure	One of the following conditions is met: The certification ECU (smart key ECU assembly) recognizes that the wire harness judging whether the vehicle is equipped with an ID code box or not is provided even though the ID code box is not registered. The certification ECU (smart key ECU assembly) receives a LIN signal from the ID code box even though the ID code box is not registered. The certification ECU (smart key ECU assembly) receives a LIN signal from the ID code box even though the wire harness judging whether the vehicle is equipped with an ID code box or not is not provided.	Misconnection of the ID code box	Smart Access	A	DTC output confirmation operation: Always

VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
Key registration will be prohibited	-

RELATED DATA LIST AND ACTIVE TEST

DTC No.	Data List and Active Test
B278D-96	-