What it means
The adaptive learning that compensates for clutch wear or hydraulic drift in an automated manual transmission has reached its limit. No more compensation is available.
At a glance
- Usually lights the check-engine light
How it works
An automated manual transmission learns clutch engagement and hydraulic behavior so it can adjust shifts as components wear or pressures drift. P2788 sets when that learned compensation reaches its allowed limit, leaving the controller without enough adjustment to maintain expected clutch operation.
Common causes
Most likely first.
- Clutch worn beyond compensation range
- Hydraulic pressure regulation has drifted
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and review the transmission's learned clutch or shift adaptation values before clearing the code.
- Check transmission fluid level and condition, and inspect for leaks that could contribute to hydraulic pressure drift.
- Review live data for clutch slip, engagement position, and shift pressure behavior to identify whether the clutch or hydraulic system is outside its normal range.
- Inspect accessible hydraulic connections and actuator wiring for leaks, damage, or loose connectors.
- Use the manufacturer's diagnostic procedure to determine whether the clutch has worn beyond its compensation range or hydraulic pressure regulation has drifted; do not assume relearning alone will correct wear.
Common fixes
- Repair any hydraulic fluid leak and restore the specified fluid level.
- Repair a confirmed pressure regulation or hydraulic control fault.
- Replace a clutch that has worn beyond the transmission's adaptation range.
- Perform the manufacturer's clutch adaptation procedure after the underlying wear or pressure fault is corrected.
Can I keep driving?
Limit driving to a short, gentle trip for diagnosis if shifts remain predictable; avoid hills, towing, and hard acceleration. If the transmission slips, misses shifts, or locks into one gear, stop safely because further driving can worsen clutch or hydraulic damage.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.