1. Insert the key for your 2002 ML430 in the ignition. Do not turn the key while in the ignition. You do not need to start the car to reset your key.
2. Press and hold the Lock button displayed on your key fob while the key is inside the cars ignition.
3. Continue to hold the Lock button down, and pull the key out of your vehicles ignition. Keep holding the Lock button even after the key is out.
4. Press the Unlock button five times in a row. Make sure to keep holding the Lock button when you do this.
5. Release the Lock button to complete the resetting process.