P2261
Turbocharger/Supercharger Bypass Valve A - Mechanical
Turbo / boost control
Generic OBD-II
Medium
What it means
P2261 means the ECM has detected a mechanical fault in the turbo or supercharger bypass (recirculation) valve — it isn't opening or closing the way the boost-control strategy expects. The result is usually poor boost control and reduced power, often with the engine falling back into a protective limp mode.
Medium
Can I keep driving? Usually drivable but expect reduced power or limp mode — a stuck bypass valve can cause over- or under-boost, so drive gently and fix it soon.
Common symptoms
What you'll notice
- Noticeable loss of power or slow acceleration
- Check-engine light on
- Whistling, fluttering, or surging under boost
- Engine may drop into reduced-power (limp) mode
Common causes
Most likely first
- Bypass/recirculation valve stuck open or closedLikely
- Torn diaphragm or broken linkage in the valveCommon
- Split, disconnected, or leaking boost/vacuum hose to the valveCommon
- Wastegate or boost-control component bindingLess often
- Carbon buildup preventing the valve from seatingLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for companion boost codes (P0234 overboost, P0299 underboost).
- Visually inspect the bypass valve and its hoses for cracks, disconnection, or oil fouling.
- Actuate the valve by hand or with a vacuum pump to confirm it moves freely and seals.
- Clean carbon buildup around the valve seat if present.
- Replace the bypass valve if the diaphragm or linkage is damaged, then clear and road-test.
FAQ
Quick answers
Is it safe to drive with P2261?+
Short-term yes, but a stuck valve can cause overboost that stresses the engine, so keep trips light and get it repaired soon.
Can I just clear P2261?+
It will return once the engine builds boost again unless the valve or its hose is actually repaired.
Related codes
Often seen with P2261
Read & clear P2261 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX