BFT garage door opener shows E15 and does not respond to open/close commands from external controls.

Safety: Turn off power before disconnecting external control wiring.

• Disconnect external controls: Remove all wires from the STEP-BY-STEP, OPEN, CLOSE, and STOP command terminals on the control board.
• Test local control: Use the onboard buttons on the BFT control board to operate the door. If it works, the fault is in the external wiring or devices.
• Check wall button: Inspect the wall push button or key switch for signs of sticking or corrosion. Test with a multimeter for proper momentary contact.
• Inspect cable runs: Look for staples through the cable, crushed sections, or moisture in junction boxes.
• Reconnect one by one: Reconnect each external control circuit individually, testing after each to identify the faulty line.