U02AF
Lost Communication With Turbocharger Turbine Inlet Valve Position Sensor
The vehicle bus reports loss of communication with the turbocharger turbine inlet valve position sensor. Position feedback for variable inlet geometry on twin-scroll/sequential turbo systems is missing.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: hard
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
Ordered by how often each turns out to be the cause.
- Bus wiring open or shortedCommon
- Module without power or groundPossible
- Module failedPossible
Parts involved
- Turbine Inlet Valve Position Sensor
- Vehicle Bus Wiring
U02AF is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.