Powertrain, generic · Fuel and air metering, auxiliary emission controls

P005F Turbocharger/Supercharger Boost Control B Supply Voltage Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

"Boost control B" is the electrically driven actuator the engine control module uses to set boost pressure: depending on the engine a pulse-width modulated solenoid or vacuum converter at the wastegate, the control valve of variable turbine vanes, or an electric actuator with position feedback. B is the second actuator, for example on the high-pressure turbocharger of a two-stage system or on the second turbocharger; it does not denote cylinder bank 2. This code concerns the supply voltage that the control module switches to the actuator (high side): it is too high, for example because of a short to battery voltage. Without control the actuator usually falls back to its rest position, which on most engines means low boost; depending on the design too much boost is also possible.

Likely causes

Supply wire shorted to battery voltage
Water or corrosion in the connector
Internal fault in the actuator
High-side driver in the engine control module faulty

Symptoms

  • Check engine light on
  • Loss of power or reduced power mode
  • Weak acceleration, noticeable turbo lag
  • Overboost possible in rare cases

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–900
Time0.5–2.5 h

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

Parts involved

boost control actuator bboost control actuator wiringengine control module

Related codes

P005EP004AP004DP006F

References: law.cornell.edu, gsi.ext.gm.com, en.wikipedia.org.