What Happens When Your Car Key Battery Dies. With what you find here you can open and start any keyless start car or truck with a dead key fob. The battery in my SmartKey for our 04 died a week or two ago so this may give you an idea of the life of the battery.

Answer 1 of 4. If your keyless entry works with a START button and theres no mechanical key slot theres still a way to start the car. With what you find here you can open and start any keyless start car or truck with a dead key fob.
In order to avoid this potential problem its important to know the warning signs of a bad or failing key fob battery.
Im speaking of my 2007 Toyota Avalon. Were here to help. If the case is where you do not have access to buy a new battery there is nothing to worry. What are the signs of a weak fob batteryAs the fob battery becomes weaker the transmitter loses its range.

