Code result
P2578
Turbocharger/Supercharger Speed Sensor A Circuit
Moderate severity
What it means
General electrical fault on the turbocharger/supercharger shaft speed sensor A — a high-frequency Hall or eddy-current sensor on the compressor shaft. The ECM uses turbo speed for overspeed protection (typically 200,000+ rpm) and for closed-loop boost on VGT systems. With no valid speed the ECM limits boost.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Open or shorted wiring
highOne of the most commonly reported causes for this code — check this first.
Aged sensor with reduced output amplitude
mediumA plausible cause — test and verify before replacing parts.
Related help
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