Powertrain, generic (extended)

P2C2C Turbocharger/Supercharger Bypass Valve B Position Sensor Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C2C flags a position signal from compressor bypass valve B that rises above the plausible top of its range, close to the sensor reference. A signal line touching 5 V or battery voltage, a broken ground wire or a defect inside the sensor are the typical findings. No manufacturer publishes P2C2C. GM's A-side counterpart P2BBD on the 2019 LT5 Corvette shows the pattern: a reading above 95 % in 10 out of 14 checks, one every 100 ms, relay voltage at least 11 V, no cranking, Type A. An Achates Power patent explains why a trustworthy reading matters: the controller compares commanded and measured opening to judge the valve. Unlike P2C29, the valve itself may still work; only its feedback is lost.

Likely causes

Signal wire shorted to reference or battery voltage
Open ground of the position sensor
Position sensor failed high

Symptoms

  • Check engine light
  • Boost limited by the engine module

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–900
Time0.5–3 h

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

Parts involved

turbo bypass valve bwiring harnessecm

Related codes

P2C2AP2C2BP2BBDP2C29

References: law.cornell.edu, gsi.ext.gm.com, patents.google.com.