P226BTurbocharger/Supercharger A Boost Pressure Too High - Mechanical
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P226B reports boost from turbocharger or supercharger A rising too high for a mechanical reason, for instance a wastegate or bypass that will not open or a seized actuator linkage, rather than a sensor or wiring fault. VW's 2014 book for the supercharged Touareg 3.0 TSI sets it when boost passes 250 kPa. GM uses the code only for European calibrations: its 2018 diesel tables list P226B as an EOBD code in the boost-system fault groups, while the US software maps the same fault group to P2263. CARB requires boosted engines to detect overboost. Where P0234 judges a deviation above the target, P226B points to a mechanical cause; P2262 describes boost that does not appear at all. To protect the engine the ECM usually reduces torque, and some engines open a relief path.
- What you may notice
- Sudden power cut or reduced-power mode under load
- MIL on
- Unusually strong surge of power just before the cut
- Likely causes
- LikelyWastegate flap seized closed by corrosion or carbon
- PossibleSeized or misadjusted wastegate or VGT actuator linkage
- PossibleVacuum or pressure line to a pneumatic actuator leaking or blocked
- RareSupercharger bypass valve not opening
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.