Powertrain, generic · Fuel and air metering, auxiliary emission controls
P00C5 Turbocharger/Supercharger B Turbine Overspeed
Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible
The control module has detected that turbocharger B runs above its permitted maximum speed. Speed is measured by a dedicated sensor per turbocharger where fitted, or estimated from a model of pressure ratio and air mass. Turbocharger B is the second turbocharger in series systems or the one on bank 2 in parallel systems. Typical causes are sticking boost control of this turbocharger or a charge-air leak; find the cause before driving on, as overspeed can destroy the turbocharger. No manufacturer description naming this exact code was found; the explanation follows its documented counterpart.
Likely causes
Boost control of turbocharger B sticking (wastegate or vanes)
Leak on the pressure side making the turbocharger work harder
Speed sensor or its wiring delivering wrong values
Operation at high altitude or software
Symptoms
- Check engine light on
- Limp mode with reduced power
- Whistling from the turbocharger
Repair estimate
DifficultyShop_onlyWorkshop job
Parts and labour€150–3,500
Time1–6 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
turbocharger bturbocharger speed sensorturbocharger vanes or wastegate
Related codes
References: law.cornell.edu, static.nhtsa.gov, patents.google.com.