Bank 1 exhaust camshaft timing over-advanced — a VarioCam performance fault.
SYMPTOMS
- Check-engine light
- Rough idle
- Power loss
LIKELY CAUSES
- Failed adjuster
- Clogged oil control valve
- Low oil pressure
DIAGNOSIS STEPS
- Verify oil level and pressure
- Replace oil control valve
- Compare actual vs commanded cam angle
RELATED PARTS
- VarioCam adjuster
- Oil control valve