Powertrain, generic · Fuel and air metering, auxiliary emission controls

P00C3 Turbocharger/Supercharger Bypass Valve B Control Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Bypass valve B is the compressor recirculation (diverter) valve of turbocharger B, not the wastegate: it lets charge air flow back to the compressor inlet when the throttle closes quickly, so the compressor does not surge. Turbocharger B is the second turbocharger in exhaust flow on series systems and the turbocharger of bank 2 on parallel twin-turbo engines. With P00C3 the circuit is electrically intact, but the valve does not behave as commanded, for example because it sticks or its position feedback is implausible. No manufacturer description naming this exact code was found; the explanation follows its documented counterpart.

Likely causes

Valve sticking or coked
Diaphragm or piston worn
Position feedback implausible

Symptoms

  • Check engine light on
  • Fluttering or surging noise when lifting off the throttle
  • Boost fluctuations, loss of power

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–350
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

turbocharger bypass valve bturbocharger bypass valve wiringengine control module

Related codes

P00C0P00C4P0039P2261

References: law.cornell.edu, gsi.ext.gm.com, ms-motorservice.com.