P2593
Turbocharger Speed Sensor B Circuit
General electrical fault on the second turbocharger speed sensor B — used on twin-turbo, sequential or two-stage installations to read the second compressor shaft speed. Same role as sensor A on the second turbo.
- 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.
- Open or shorted wiringCommon
Parts involved
- Turbo Speed Sensor B
- Sensor Wiring
P2593 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.