DTC U0129: Lost Communication with Brake System Control Module [10/2017 - 12/2021]: Description

The Controller Area Network (CAN) is a serial data communication system for real time applications. This is a vehicle multiplex communication system which has a high communication speed (500 kbps) and a high level of ability to detect malfunctions. By pairing the CANH and CANL bus wires, the communication on the CAN is performed using the voltage differential between the wires.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
U0129	Lost Communication with Brake System Control Module	All of the following conditions are met for 2.22 seconds or more (1 trip detection logic): Ignition switch ON Battery voltage is 10.5 V or more No communication between ECM and skid control ECU	Wire harness (CANL and CANH circuit) ECM Brake actuator assembly (Skid control ECU) CAN communication system	Comes on	DTC stored