What does code U02AF mean?

DTC codes / U02xx · Lost communication with a control module / U02AF

U02AFLost Communication With Turbocharger Turbine Inlet Valve Position Sensor

U02AF is a generic communication fault indicating that a control module on the vehicle's controller area network (CAN) bus has lost contact with the turbocharger turbine inlet valve position sensor, which is typically a smart sensor that communicates over a dedicated serial data line rather than a simple analog voltage. The module that monitors this sensor, often the engine control module (ECM) or a dedicated turbo control module, has stopped receiving valid position messages from the sensor for a calibrated period, so it sets this code and may command the turbocharger into a default or limited-boost strategy.

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.