Robot mower shows E13 and refuses to start; the display may indicate "PIN" or a security warning.

Safety first: Ensure the mower is OFF when not actively entering codes to prevent accidental blade start.

Steps:

• 1. Verify PIN: Enter the correct PIN code slowly. Refer to your Yard Force manual for the default PIN if it has never been changed.
• 2. Wait lockout period: If too many incorrect attempts were made, wait the specified lockout time (often 10–20 minutes) before trying again.
• 3. Check keypad: Inspect the keypad or control panel for stuck or damaged buttons. Clean gently and ensure no water ingress.
• 4. Battery reset: Turn OFF the main switch, disconnect the battery for 5–10 minutes, then reconnect and try again.
• 5. Contact support for PIN reset: If the PIN is lost, contact Yard Force support with proof of ownership. They can provide a reset procedure or a service code specific to your model.

If the keypad or display module is faulty, it may need replacement along with reprogramming of the main PCB.