P2564: Turbocharger Boost Control Position Sensor A Circuit Low
What to do
The engine will feel flat and may go into reduced power. It is not usually damaging, so getting it to a workshop is fine, but it will not clear itself. Ask for the wiring to be inspected properly before the sensor is replaced — this loom lives against a turbocharger that runs red hot, and heat-damaged insulation is one of the commonest findings. A new sensor on a damaged loom fails in exactly the same way.
What this code means
The vane position circuit reads below its valid range — a short to ground, an open reference supply, or a sensor that has failed to the bottom of its scale.
With no usable position feedback the module cannot control boost and defaults the vanes to a safe position, so the engine runs without meaningful boost control. That is the flat, gutless diesel the family is known for.
Heat is the reason this circuit fails more often than most. The sensor and its wiring are mounted on or beside a turbocharger housing that runs red hot under load, so insulation hardens, cracks, and eventually lets a conductor touch the housing it is strapped to. Wiring damage is therefore a leading cause here rather than an afterthought, and a repair that reroutes or re-sleeves a chafed loom is a real fix rather than a bodge.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Heat damage to sensor or wiring · moderate
- Faulty turbocharger vane position sensor · moderate
Less common
- Corroded or loose connector · easy
- Failed sensor reference voltage supply · moderate
Symptoms
Components involved
Information, not instruction
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