Powertrain
generic / SAE
P00C4
Turbocharger/Supercharger Bypass Valve B - Mechanical
Mechanical fault detected at bypass valve B — broken linkage, jammed valve, or seized actuator rod. Boost control tracks commanded vs. actual manifold pressure; persistent deviation means wastegate, vanes, hose or actuator are not delivering the requested pressure.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number– / C4
Possible causes
- Linkage broken or seized high
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–2000 €
- Estimated time: 2–8 h
- Component: bypass valve b
- Component: linkage
- MIL / check engine light
- emissions-relevant
- drive cycle required
- limp mode possible
Sources
References
sae:J2012