What does code U02AC mean?

DTC codes / U02xx · Lost communication with a control module / U02AC

U02ACLost Communication With Turbocharger/Supercharger Boost Control A

U02AC is a generic communication fault indicating that a control module has lost contact with the turbocharger or supercharger boost control actuator circuit, typically over a dedicated serial data bus. The computer detects this when expected messages from the boost control module stop arriving within a defined time window, setting the code and usually illuminating the check engine light.

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.