Display shows E20 and the mower will not start; often after firmware updates or power issues.

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Interrupted firmware update, Corrupted firmware image, Incompatible control panel replacement, Internal memory fault

How to Fix / Troubleshooting

Safety first: Ensure the mower is on a stable surface with blades stopped.

Power cycle: Switch the mower OFF, disconnect from the docking station, wait 2–3 minutes, then reconnect and switch ON.
Check for update instructions: Consult the Stihl iMOW manual or dealer for any available firmware recovery procedures specific to your model.

Most firmware-related E20 errors require dealer-level tools to reflash or replace the main control PCB. Do not attempt to open or modify the PCB yourself.

Repair Difficulty

Professional Required 5/5

Required Part

Main Control PCB

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