U0675Lost Communication With Turbocharger/Supercharger Speed Sensor A
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- A speed sensor in the bearing or compressor housing lets the controller watch how fast the turbocharger rotor spins, mainly to keep it below its overspeed limit; a BorgWarner patent (US9353760B2) describes such a sensor and gives that reason, and CARB names turbocharger/turbine speed among the data diesel vehicles must output. Classic sensors send a pulse train whose faults are P2578 to P2582. U0675 applies when sensor A delivers the speed as a digital message and those messages are missing or invalid. No manufacturer documents this code publicly. Without a speed value the controller cannot tell how close the rotor is to its limit, so it will usually cap boost and engine power until the fault is gone.
- What you may notice
- Check engine light
- Boost and power limited
- Noticeably weaker acceleration at higher loads
- Likely causes
- LikelySensor wiring near the turbocharger heat-damaged or broken
- PossibleConnector loose, oily or corroded
- PossibleSpeed sensor electronics failed
- RareEngine controller input or software fault
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.