What does code U0120 mean?

Q: What does code U0120 mean?

Lost Communication With ABS/Traction Control Module. U0120 is a network communication code indicating that the engine control module (ECM) or another primary module has lost contact with the anti-lock brake (ABS) and traction control module over the vehicle's controller area network (CAN) bus. The computer sets this code when it expects regular status messages from the ABS module but receives none for a set period, often because the module is offline, the bus wiring is damaged, or power and ground to the module are interrupted.

DTC codes / U01xx · Lost communication with a control module / U0120

U0120Lost Communication With ABS/Traction Control Module

U0120 is a network communication code indicating that the engine control module (ECM) or another primary module has lost contact with the anti-lock brake (ABS) and traction control module over the vehicle's controller area network (CAN) bus. The computer sets this code when it expects regular status messages from the ABS module but receives none for a set period, often because the module is offline, the bus wiring is damaged, or power and ground to the module are interrupted.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaLost communication with a control module

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.