Powertrain, generic (extended)

P2C7E Turbocharger Turbine Inlet Valve Motor Driver Overtemperature

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C7E indicates that the driver circuit for the turbine inlet valve motor has grown too hot. Driver chips monitor their own junction temperature and switch off beyond a limit, as the data sheet of NXP's MC33926 H-bridge shows. No manufacturer documents P2C7E publicly; the closest published example is GM's 3.0-litre diesel, where P2B99 for the exhaust pressure valve sets once the H-bridge driver exceeds 170 °C in 240 of 300 samples (Type A, table 25OBDG04B). Heat builds up when the motor has to hold against a stiff or binding valve for long periods, when windings are partly shorted, or when an actuator with built-in electronics sits close to hot turbo parts, a risk the Korean actuator patent also names. After shutdown the valve is uncontrolled and boost is reduced. P2C7D is the overcurrent fault.

Likely causes

Binding valve that keeps the motor under constant load
Partially shorted motor windings raising current and heat
Actuator electronics overheated by missing heat shield or poor cooling
Defective driver stage reporting overtemperature

Symptoms

  • Loss of boost after a longer drive or under high load
  • Check engine light, possibly limp mode
  • Fault may disappear after the engine has cooled down

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–2,500
Time1–5 h

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

Parts involved

turbo turbine inlet valvewiring harnessecm

Related codes

P2C7DP2C7BP2C7CP2B99

References: nxp.com, gsi.ext.gm.com, patents.google.com.