Powertrain, generic (extended)

P2C7C Turbocharger Turbine Inlet Valve Supply Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C7C reports that the voltage feeding the turbine inlet valve actuator is too low. Electric turbo actuators of this kind combine a DC motor, gearing and a position sensor and rely on a stable feed; BorgWarner's patent on such an actuator adds a spring that returns the valve to a default position when power is lost. No manufacturer documents P2C7C publicly. GM uses a comparable check on the exhaust pressure valve of its 3.0-litre diesel (P2B98, table 25OBDG04B): a fault when the motor supply drops below 6 V in 240 of 300 samples while the main relay delivers more than 11 V, Type A. Likely culprits are a blown fuse, a weak relay, corroded pins or a broken feed wire; a flat battery alone should not cause it. Boost control is curtailed. Faults in the control lines are P22CF to P22D1.

Likely causes

Blown fuse or faulty supply relay for the actuator
Corroded or loose pins at the actuator connector
Chafed or broken feed or ground wire near the hot turbo area
Defective supply output in the control module

Symptoms

  • Check engine light
  • Low boost and reduced power
  • Further turbo actuator codes stored at the same time

Repair estimate

DifficultyMediumDIY possible
Parts and labour€10–400
Time0.3–2 h

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

Parts involved

turbo turbine inlet valvewiring harnessecm

Related codes

P22CFP22D0P22D1P2C7DP2B98

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