Robot mower displays E9 and stops randomly during operation, often on uneven ground.

Safety first: Switch OFF the mower and move it to a flat area before troubleshooting.

• Check slope: Verify that the working area does not exceed the maximum slope specified for your LandXcape model. Relocate the boundary wire to exclude steep banks.
• Inspect wheels and casters: Ensure the front caster wheel rotates freely and is not jammed with grass or stones. A stuck caster can cause tipping and trigger the roll sensor.
• Clean underside: Remove heavy grass build‑up from the underside that could unbalance the mower.
• Check roll sensor module: Inside the mower, locate the roll/overturn sensor (often a small tilt switch or accelerometer board). Confirm it is securely mounted and its connector is tight.
• Test on flat ground: Run the mower in a flat, open area. If E9 still appears frequently, replace the LandXcape roll/overturn sensor module.