Will Prius start when key battery is dead?
Hi Elton! My understanding is that there is a key hidden in the FOB to help you get into the car and then there is a slot in the car than you plug the FOB into to start the car. The battery is a standard coin type battery that is readily available, but there's no reason it should be dead at this point. Here's a discussion about various Prius issues that should answer some questions. Hope it helps. Good luck! http://townhall-talk.edmunds.com/direct/view/.f1171ad
Unless you have the kind of key where you don't have to insert it at all (it only has to be in the car or around the car to start or unlock." If thats the case you would need to replace the battery. Call your dealer, see what they say.
I inquired at my dealer and the answer is that you need to put the key into the slot on the dash to make a dead battery key work.
OK it's been 9 years since you posted the question, but the right answer is, according to the owner's manual AND I have actually done this: you hold the dead key as close to the face of the START button and if there is a slight bit of juice left in its key- battery it will start by 1) press the brake and 2) press the start button while holding the key as close to the start button as possible. THIS WORKS or, you can replace the battery in the key very easily use CR1632 which is a 3-volt slug type battery you can get anywhere that sells batteries. TO CHANGE THE KEY BATTERY YOURSELF google search "how change key battery prius?" Some year-models require you to remove 4 screws to access the battery but you no longer have to remove screws to access the battery slot if you have a 2012 or later. Do a google search on your model year.
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