P2579
Turbocharger/Supercharger Speed Sensor A Circuit Range/Performance
Turbo speed sensor A is electrically intact, but the speed reading does not match the model — for example a speed that does not climb when boost rises, drifts away from the air-mass-flow estimate, or jumps. Often blade-fouling, a contaminated sensor tip or aged element.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Common causes
Ordered by how often each turns out to be the cause.
- Oil-contaminated sensor tipCommon
- Aged Hall elementPossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- Turbo Speed Sensor A
- Turbocharger
P2579 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.