Powertrain, generic (extended)

P22C5 Turbocharger Compressor Outlet Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P22C5 flags an open or broken drive circuit for the turbocharger compressor outlet valve. That valve sits in the charge-air path downstream of a compressor and decides whether this compressor feeds the engine, for example in register or two-stage charging or next to an electric auxiliary compressor. While the output is switched off, the engine control module compares the voltage on its driver with the level expected for an intact load; a reading typical of a cut wire or an unplugged connector sets the code. California OBD rules treat such boost actuators as monitored output components. No manufacturer publicly documents P22C5 itself; Mercedes-Benz uses the related stuck codes P22C8 and P22C9 on the M256 engine. With the valve unpowered, the module usually limits boost and power.

Likely causes

Valve connector loose, unplugged or corroded
Broken wire in the valve harness, often near hot turbo parts
Open actuator coil inside the compressor outlet valve
Faulty output stage in the engine control module

Symptoms

  • Check engine light on
  • Reduced power because boost is limited
  • Weak or delayed pull at the speed where the second boost path should join

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–450
Time0.5–2.5 h

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

Parts involved

turbochargerdiverter valve

Related codes

P22C6P22C7P22C8P22C9P22CA

References: law.cornell.edu, patents.google.com, static.nhtsa.gov.