Turbocharger/Supercharger Bypass Valve A - Mechanical
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.
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.
Real-world scan data
Appears alongside · share of P2261 scans
Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.
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?+
Can I just clear P2261?+
Related codes
Read & clear P2261 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.