OBD-II code · Powertrain (generic)
P03EF A Camshaft Profile Actuator C Control Performance/Stuck Off (Bank 1)
Cam profile actuator A position C is electrically OK but does not engage when commanded. The cam phaser actuator adjusts intake/exhaust timing under load — a stuck or slow phaser kills mid-rpm torque and can throw correlation codes between cam and crank.
Is it safe to drive with P03EF?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyLock pin or oil supply restricted
- Less likelyCarbon or debris buildup preventing free movement
- Less likelyComponent wear with age - mechanical play
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1.5–5 h
- Emissions test
- Likely to fail
- Parts involved
- Camshaft Position Actuator
Related codes
- P03ECA Camshaft Profile Actuator C Control Circuit/Open (Bank 1)
- P03F4B Camshaft Profile Actuator C Control Performance/Stuck Off (Bank 1)
- P03EDA Camshaft Profile Actuator C Control Circuit Low (Bank 1)
- P03EEA Camshaft Profile Actuator C Control Circuit High (Bank 1)
- P03F0A Camshaft Profile Actuator C Control Stuck On (Bank 1)
- P03F1B Camshaft Profile Actuator C Control Circuit/Open (Bank 1)
- P03F2B Camshaft Profile Actuator C Control Circuit Low (Bank 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.