When an automatic gate starts to close and immediately reverses, the operator is usually responding to an obstruction signal or resistance during travel. The safety system may be working correctly even when nothing obvious appears to be in the opening.
Common causes
- A blocked, dirty or misaligned closing photo eye.
- A safety edge that is being compressed or has a monitored-circuit fault.
- A vehicle loop or access-control input that is holding the gate open.
- Debris, sagging, hinge resistance, a damaged roller or contact with the ground.
- A limit, position-feedback, RPM or force condition in the operator.
Safe checks you can make
- Move vehicles away from the opening and any marked loop area.
- Clear the complete gate path and wipe accessible photo-eye lenses.
- Watch where the reversal occurs and whether it happens at the same point every time.
- Look for visible sagging, track debris, impact damage or a sensor that has been bumped.
- Record the diagnostic code and weather conditions.
Safety: Do not increase force to make a binding gate close, and do not bypass a photo eye, safety edge or monitored input.
When to call KDI
Call if the reversal repeats after the opening and sensors are clear, if the gate contacts anything, or if it shows a stall, force or monitored-device fault. Request automatic gate service or call (843) 730-0215.
Reviewed September 22, 2026. Procedures and diagnostic codes vary by operator model and production generation; use the manual for the exact equipment installed.