Robot mower will not start; display shows E001 immediately after power‑up

Safety first: Remove the mower from the lawn, flip the main power switch OFF, and remove the battery or disconnect the battery connector if accessible. Wear cut‑resistant gloves.

• Check the red STOP button: On most Cub Cadet robot mowers, press the red STOP button fully down, then twist or pull it to release. Verify it pops up freely.
• Clean around the button: Grass, dust, or mud can jam the button. Use a soft brush and compressed air to clean the button area. Do not use high‑pressure water.
• Inspect the button travel: With power OFF, press the button repeatedly. It should move smoothly and spring back. If it feels gritty or sticks, the switch may be failing.
• Check wiring (advanced): Remove the top cover per the service manual. Inspect the stop button wiring harness to the main PCB for loose plugs, corrosion, or damaged insulation. Reseat connectors firmly.
• Power cycle: Reconnect the battery, turn the main switch ON, and restart the mower. If E001 persists after confirming the button is released, the stop switch or main board likely needs replacement.

If you are not comfortable opening the housing or working near the battery, contact a Cub Cadet service center.