Bank 1 camshaft timing is more retarded than commanded — a VarioCam performance fault.
SYMPTOMS
- Check-engine light
- Rough idle
- Hesitation
- Power loss
LIKELY CAUSES
- Stuck or failed VarioCam adjuster
- Clogged oil control valve
- Low oil pressure
- Worn cam timing components
DIAGNOSIS STEPS
- Verify oil level and pressure
- Clean or replace the oil control valve
- Compare actual vs commanded cam angle
- Inspect timing mechanically if it persists
RELATED PARTS
- VarioCam adjuster
- Oil control valve