What does code U0657 mean?

DTC codes / U06xx · Network communication / U0657

U0657Lost Communication With Turbocharger/Supercharger Bypass Valve A Position Sensor

U0657 is a network communication code indicating that a control module has lost contact with the position sensor for the turbocharger or supercharger bypass valve 'A'. The computer detected that expected data messages from that sensor stopped arriving over the vehicle's communication bus, not that the sensor itself has necessarily failed.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaNetwork communication

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