Cause
Disconnected wastegate vacuum hose
The small hose carrying vacuum or pressure to the wastegate actuator, split, perished or off its spigot. It is a trivial part with a large effect, and it is worth checking before anything expensive because the symptoms are identical to a failed actuator or a seized turbocharger.
Which way the fault presents depends on how the system rests. A vacuum-actuated wastegate is held closed by spring and opened by vacuum, so losing the signal leaves it shut — overboost, and a protective power cut. A pressure-actuated one is the reverse: losing the signal leaves it open, giving underboost and a flat engine. Establishing which this vehicle uses tells you what to expect before anything is measured.
These hoses fail from heat and age rather than damage. Silicone and rubber harden over years next to a turbocharger until they crack at the bend or shrink off the spigot — and the split is frequently on the underside or behind something, which is why a quick look misses it.
Check the whole vacuum circuit rather than just this hose, including the reservoir and its non-return valve. A leak anywhere in it produces the same result, and a system that has lost one hose to age usually has others the same age.
Typically an easy fix. Often worth checking before paying anyone to look.
Some of these codes mean you should stop driving
1 of the 7 codes this can cause indicate a fault where continuing to drive risks damage or is unsafe. Which one you have matters more than the cause does — read the code's own page before deciding.
Codes this can cause (7)
Codes where this is a likely explanation first, rather than merely a possible one.
- P0244 Turbocharger/Supercharger Wastegate Actuator A Range/Performance Likely for this code High
- P0248 Turbocharger/Supercharger Wastegate Actuator B Range/Performance Likely for this code High
- P0299 Turbocharger/Supercharger A Underboost Condition Likely for this code High
- P0234 Turbocharger/Supercharger A Overboost Condition Stop driving High
- P056E Cold Start Turbocharger/Supercharger Boost Control A Performance Moderate
- P226C Turbocharger Boost Control A Slow Response Moderate
- P22CE Turbocharger Compressor Outlet Switching Valve Stuck Closed High
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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.
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