DTC U0073, U0100, U0129: Control Module Communication Bus OFF; Lost Communication with ECM/PCM "A1"; Lost Communication with Brake System Control Module: Description

The power steering ECU receives signals from the ECM and the skid control ECU via the CAN communication system.

DTC DESCRIPTION TABLE

DTC No.	DTC Detection Condition	Trouble Area
U0073	Control module communication bus off	CAN communication system
U0100	Lost communication with ECM/PCM "A"	CAN communication system ECM
U0129	Lost communication with brake system control module	CAN communication system Skid control ECU

HINT:

When 2 or more DTCs starting with [U] are output simultaneously, inspect the connectors and wire harness of each ECU.
If DTC U0100 is output, first erase the DTCs. Then turn the ignition switch from off to on (IG). If DTC U0100 is not output again, there is no malfunction.