DTC U0129: Lost Communication with Brake System Control Module [11/2021 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

The ECM and skid control ECU (brake actuator assembly) send and receive signals via CAN communication.

If a communication error occurs between the ECM and skid control ECU (brake actuator assembly), the ECM stores this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
U0129	Lost Communication with Brake System Control Module	Both of the following conditions are met for 2.22 seconds or more (1 trip detection logic): Engine switch on (IG) No communication between ECM and skid control ECU (brake actuator assembly)	CAN communication system Skid control ECU (brake actuator assembly) ECM	Does not come on	DTC stored