P2581: Turbocharger/Supercharger Speed Sensor A Circuit High
What to do
The engine will feel flat, possibly with a reduced power warning, because the module limits boost when it cannot read turbocharger speed.
If any work has recently been done around the turbocharger, exhaust manifold or particulate filter, mention it straight away. This connector is disturbed to reach all of those and is easy to leave unplugged in a space that cannot be seen without a mirror. That check is free and is the commonest answer in that situation.
One reassurance: despite the word "high", this code does not mean the turbocharger is spinning too fast. It means the circuit voltage is out of range and the module has no usable reading.
What this code means
The turbocharger speed circuit reads above its valid range — an open circuit, a disconnected connector, or a short to supply.
The important distinction on this page is between a circuit reading high and a turbocharger genuinely spinning fast. They are different findings and they belong to different codes. This one is electrical: the voltage on the line is outside what any real speed could produce, so the module discards it. A shaft speed that is real but excessive is P2579, and that is the one with a damaged turbocharger behind it. Do not read this code as an overspeed warning — it is the module saying it has no usable signal at all.
An open circuit is the usual finding. This sensor is routinely disturbed to reach other things in a crowded, hot space — the turbocharger itself, the exhaust manifold, the particulate filter — and its connector is small, out of sight and easy to leave unmated.
As everywhere in this family, losing the signal makes the module cap boost, so the engine feels flat.
Likely causes
Start here
- Disconnected sensor connector · easy
- Open circuit in sensor wiring · moderate
- Faulty turbocharger speed sensor · moderate
Less common
- Heat damage to sensor or wiring · moderate
- Wiring shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
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