P2581
Turbocharger/Supercharger Speed Sensor A Circuit High
Turbo speed sensor A signal voltage above the upper limit — short to reference voltage or open signal return.
- 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.
- Signal wire shorted to reference voltageCommon
- Connector pins corroded - high contact resistanceLess likely
- Supply wire pinched against B+ sourceLess likely
Parts involved
- Turbo Speed Sensor A
- Sensor Wiring
P2581 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.