P2711
Unexpected Mechanical Gear Disengagement
The transmission disengaged mechanically without a corresponding command. The vehicle can free-wheel, which is a safety concern. Often a hydraulic or hardware fault inside the gearbox.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Clutch piston seal failure releases gearCommon
- Sudden hydraulic pressure lossPossible
Parts involved
- Transmission Internal
- Hydraulic Control Unit
P2711 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.