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

P003B Turbocharger/Supercharger Boost Control B Position Exceeded Learning Limit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

The electric boost actuator B positions the variable turbine vanes or the wastegate and reports its position through a sensor. In a learning run, for example with the engine warm at idle or after switching off, the control module drives the actuator to its mechanical end stops and stores the sensor values as reference. P003B is set when a learned end position or the total travel lies outside the permitted limits. Typical reasons are worn or sticking vanes or linkage, a faulty actuator, a broken actuator lever, or a replacement actuator that has not been learned in. B denotes the second actuator, for example on the second stage of a two-stage system.

Likely causes

Electronic actuator or its control module faulty
Vane mechanism, sector gear or linkage worn or sticking
Replacement not learned in, or learning run aborted (e.g. low voltage)
Actuator lever broken
Position sensor or its wiring faulty

Symptoms

  • Check engine light on
  • Reduced power mode
  • Underboost or overboost codes possible
  • Sometimes no noticeable symptoms

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€400–3,500
Time1–3 h

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

Parts involved

boost control actuator bactuator position sensorturbocharger vanes or wastegate

Related codes

P003AP004AP004BP2587P0234P0299

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