A measured gear ratio does not match the commanded gear.
SYMPTOMS
- Check-engine light
- Slipping
- Harsh or wrong-gear shifts
- Limp mode
LIKELY CAUSES
- Low/degraded transmission fluid
- Clutch/mechatronic fault
- Internal wear
- Solenoid fault
DIAGNOSIS STEPS
- Read TCU sub-codes with a Porsche-capable tool
- Check fluid level/condition
- Compare commanded vs actual gear in live data
RELATED PARTS
- PDK fluid
- Mechatronic unit
- Clutch