OBD-II code · Powertrain (generic, extended)
P2594 Turbocharger Speed Sensor B Circuit Range/Performance
Turbo speed sensor B is electrically intact, but the speed reading does not match the boost or air-mass model — same failure mode as sensor A performance fault, applied to the second turbo.
Is it safe to drive with P2594?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOil-contaminated sensor tip
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.6–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Turbo Speed Sensor B, Turbocharger
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.