Powertrain, generic · Ignition system or misfire

P03F5 B Camshaft Profile Actuator C Control Stuck On Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

With a sliding camshaft, the exhaust camshaft (camshaft B) carries movable cam pieces with several lift profiles; solenoid actuators shoot a pin into a groove in the piece and shift it axially. Actuator C is the third of these actuators – not a profile position. The only known user is GM's 2.7-litre turbo four (L3B, three-step sliding cam, from model year 2019). P03F5 means the actuator stays on: its pin remains extended although it was commanded off. No manufacturer document available to us uses this code – GM monitors its exhaust actuators only for circuit faults and uncommanded extension; the description follows the intake counterpart P03F0, where GM sets the code if the pin does not retract by the end of the engine cycle.

Likely causes

Pin sticking in the actuator (sludge, wear)
Return ramp of the shift groove damaged or cam piece sticking
Solenoid stays energized (control wire shorted to ground)
Hall feedback faulty

Symptoms

  • Check engine light on
  • Ticking or rattling at the camshaft carrier
  • Misfire, rough idle or less power in the wrong lift profile
  • Lift switching and cylinder deactivation out of service

Repair estimate

DifficultyHardWorkshop job
Parts and labour€200–2,500
Time1–8 h

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

Parts involved

camshaft profile actuator c exhaustsliding camshaftactuator wiringengine control module

Related codes

P03F4P03F2P03F0P005BP037C

References: law.cornell.edu, gsi.ext.gm.com, patents.google.com.