DTC U0291-00: Lost Communication with Gear Shift Control Module "B" (System 2) Missing Message [11/2021 - ]: Description

WARNING: This page is about a different car, the 2025 Lexus NX 350h, 2024 Lexus NX 350h, 2023 Lexus NX 350h, and 2022 Lexus NX 350h. However, it is still accessible from the selected car via links, so may be relevant.

The shift control ECU receives or sends a signal to and from the shift actuator ECU via CAN communication.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Warning Indicate	DTC Output from	Priority	Note
U0291-00	Lost Communication with Gear Shift Control Module "B" (System 2) Missing Message	When the ignition switch is ON (IG) and the auxiliary battery voltage is a certain value or more, a CAN communication malfunction with the shift actuator ECU is continuously detected (1 trip detection logic)	Shift control actuator assembly (Shift actuator ECU) Transmission floor shift assembly (shift control ECU) Hybrid vehicle control ECU Battery ECU assembly Radio and display receiver assembly Combination meter assembly Mobile wireless charger cradle assembly Wire harness or connector	Does not come on	Multi-information Display Error Message Displayed	Hybrid Control	B	SAE: U0291