Hi there. Just joined. We have a 2016 Prius, owned since 2019. A few weeks ago, my wife heard a beep coming from the car while she was unloading packages, and then her key fob stopped working. It will start the car (if you hold it to the ON switch). But all remote other functionality is gone (locking/unlocking won’t work). I verified Smart Cancel is off, and changed to a fresh battery. My key fob is unaffected. Any ideas?
Why Isn’t My Car Remote Working? Have you ever gone to unlock your car with your key fob, only to realize it wasn’t working? This occurrence isn’t all that uncommon. Key fobs are pieces of machinery that go through a lot more wear and tear than most electronics, so they can sometimes have little problems throughout their lifecycle. Luckily for you, we’re going to take you through the top reasons your key fob isn’t working and how to fix it. Determining the Problem with your Key Remote: First, you must find the root cause of the problem. The first step in figuring out what is wrong with your key remote is verifying that the problem is actually with the key remote. If you have a second key remote, and you haven’t already done so, check to make sure this works so you can be certain it isn’t a problem with the door lock functionality. If the backup remote is able to unlock the doors, then you know that it is a problem with the key fob and not with your vehicle’s locking system. If this remote doesn’t work, it is either your door locks or it could be that both remotes aren’t working as they should be. At this point, you’ll want to try unlocking the doors with your physical key, which can usually be found inside the key fob if you have a push-button start. Sometimes, key holes in the vehicle will be hidden. If you can’t find your key hole or aren’t comfortable accessing it for some reason, this may be the time to consult a professional. If you can unlock the car manually, the locks are working mechanically. There could still be a problem with the electrical system, which you can check by toggling the automatic lock and unlock buttons in your vehicles interior. Check Your Battery Next, you’ll want to determine if your battery is the problem. You can either measure the voltage with a multimeter or just swap out your battery for a new one. If your remote works after this step, then you’re good to go. But, if it doesn’t work, there could be other problems with your remote. This could be a number of issues including a broken battery contact or problem with the buttons. It could even be that your vehicle may have forgotten your fob, in which case, it will need to be reprogramed. These issues should be looked at by your service technician or dealership personnel who will be able to fix the remote or help you replace it.
You could have a stuck button. Try cleaning the key fob to make sure no button is not "stuck" down. You definitely want to remove the battery from the key fob first, so if it decides to start working you won't have to listen to the horrible alarm going off. Or as one other poster called it, "The Evil Sound." I wish you the best of luck and hope this helps.
There's a small red LED in the upper left corner of the fob near the "Lock" button that blinks when any button is pressed. You may need to be in low light (shade) to be able to see it. This will tell you if your fob is transmitting. This will eliminate the fob from the issue. If the red LED is blinking upon keypresses, your fob is okay.