DTC U0103-87: Lost Communication with Gear Shift Control Module "A" Missing Message [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.

The ECM and shift control ECU (transmission floor shift assembly) send and receive signals via CAN communication.

If a communication error occurs between the ECM and shift control ECU (transmission floor shift assembly), the ECM stores this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	DTC Output from	Priority	Note
U0103-87	Lost Communication with Gear Shift Control Module "A" Missing Message	All of the following conditions are met for 1.64 seconds or more (1 trip detection logic): Ignition switch ON Battery voltage is 10 V or higher No communication between ECM and shift control ECU (transmission floor shift assembly)	CAN communication system Shift control ECU (transmission floor shift assembly) ECM	Does not come on	Engine	B	SAE Code: U0103 DTC for Mexico Models: Applies