Powertrain, generic · Fuel and air metering (injector circuit)

P0250 Turbocharger/Supercharger Wastegate Actuator B High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

The wastegate lets exhaust bypass the turbine to limit boost; actuator B is either a pulse-width-modulated solenoid on a pneumatic wastegate can or an electric actuator with a position sensor. B is the second turbo or actuator, so B codes only exist on engines with two. P0250 means the control circuit of actuator B reads high: the control wire is shorted to voltage, checked with the driver on. GM's LGW twin-turbo sets it at less than 0.5 Ω to battery voltage in 10 of 20 samples with the warning light in the first trip; older GM modules need two trips. Ford reports it on pneumatic wastegates after 2–3 s. Valve B can no longer be controlled, so that side runs on base boost.

Likely causes

Control wire of wastegate B shorted to voltage
Winding shorted internally (overcurrent)
Connector corroded or damp
Driver stage in the engine module faulty

Symptoms

  • Check engine light on
  • Clearly less power, boost only at base level
  • Uneven boost between the turbos
  • Reduced engine power message possible

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–400
Time0.5–2.5 h

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

Parts involved

wastegate actuator bwastegate solenoid valveactuator wiring

Related codes

P0247P0249P0248P0246P0299

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com.