OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

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.

SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number3 / EF

Possible causes

  • Lock pin or oil supply restricted high
  • Carbon or debris buildup preventing free movement low
  • Component wear with age - mechanical play low

Symptoms

  • Check engine light on
  • Power loss especially in mid-rpm range
  • Possible rough idle or stalling
  • Increased fuel consumption

Inspection / repair

  • Difficulty: hard
  • DIY: shop recommended
  • Estimated cost: 200–2000 €
  • Estimated time: 1.5–5 h
  • Component: camshaft position actuator
  • MIL / check engine light
  • emissions-relevant

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication