P0046: Turbocharger/Supercharger Boost Control A Circuit Range/Performance
What to do
Expect reduced power. Have actual boost compared against commanded boost on live data before any part is bought.
What this code means
The boost control circuit is electrically healthy but boost is not tracking the commanded target. On variable-geometry turbochargers this very often means the vane mechanism has seized with soot rather than that the solenoid has failed — a common outcome on diesels used mainly for short journeys. The distinction matters, because one is a cheap solenoid and the other is a turbocharger off the engine.
Likely causes
Start here
- Seized variable geometry turbocharger vanes · specialist
- Failed boost control solenoid · moderate
- Boost leak in charge pipework · moderate
Less common
- Faulty wastegate actuator · moderate
- Vacuum leak in intake manifold or hoses · moderate
- Worn turbocharger · specialist
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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