Safety first: Switch OFF the mower and remove the battery. Support the mower securely before working near the wheels.

Check for external obstructions: Inspect both NAC drive wheels. Remove wrapped grass, roots, or string from the wheel treads and axles.
Spin wheels by hand: Each wheel should rotate with some resistance from the gearbox but without grinding or locking. A wheel that is completely stuck or very rough indicates internal gearbox damage.
Inspect wheel housings: Look for cracked plastic around the wheel motor module or signs of impact.
Check connectors: Remove the side covers to access the wheel motor connectors on the main harness. Reseat the connectors and check for corrosion.
Test individually (advanced): With the mower safely supported and covers on, reconnect power and start a test. Observe which wheel fails to move when E05 appears. This identifies the faulty side.
Replace module if needed: If cleaning and connector checks do not resolve the issue, replace the affected NAC drive wheel motor/gearbox module as a complete unit.

Warning: Do not run the mower with covers removed. Keep hands clear of wheels during any powered tests.

Robot lawnmower displays E05 Wheel Blocked; one or both drive wheels do not turn.

Possible Causes