Is it the battery, the fob or the car?
Start with the battery. A small coin cell inside the fob powers the buttons and, on push-to-start cars, the signal the car listens for. As it fades, range drops first: one week the fob works from the porch, the next only from beside the door. A dash message saying the key isn't detected points the same way.
If a fresh battery changes nothing, the fob has usually lost its programming or been damaged, or the car isn't hearing it. The checks below narrow it down from the driver's seat, with no tools.
Checks you can do yourself
- Swap the battery. The size is printed on the old one. The fob battery guide walks through opening the case without cracking it.
- Try your other fob. If the spare works and this one doesn't, the car is fine and the trouble is in the fob. If neither works, look at the car.
- Watch the little light. Many fobs have an LED that blinks with each press. No blink with a brand-new battery usually means a broken contact or a damaged board.
- Check the car's own battery. Dim dash lights or a slow start mean the car itself may be too weak to answer any fob. That needs a battery fix, not a key.
Stuck with a dead fob on a push-to-start car right now? The dead fob guide shows how to get in with the hidden blade and get the engine running today. This page is about fixing the fob for good.
Why fobs stop working
Batteries are the usual cause, but not the only one. Fobs ride in pockets, hit concrete and go through the wash. Over time the rubber button pads wear through, the solder holding the battery contacts cracks, or moisture corrodes the circuit board.
A fob can also forget the car, for example on some older vehicles after the car battery is replaced, or after an attempt to add a key stopped halfway. The light still blinks, but the car ignores it. Cold saps coin cells too, so a weak fob often quits first on a freezing morning.
What happens when we come out
We start by testing the fob you have. If it still transmits and the car ignores it, many vehicles let us program it back in, so you keep the fob you own. If the board is damaged, we program a new remote, or cut and program a new flip key, remote-head key or smart key at the car.
If a fob is lost, we can often delete it from the car so whoever finds it can't start the engine. Before we leave, we test lock, unlock, trunk, panic and, where the car has it, remote start.
Bought a replacement online? Read us the part number or FCC ID from the back when you call. We check compatibility first, since many online fobs can't be programmed, and promise nothing for third-party keys. The online fob guide explains more.
Before you pick up the phone
- Which car it is (year, make, model) and whether it starts with a button or a turned key.
- How many fobs you have, and whether any of them still work.
- Where the car is sitting: your driveway, the lot at work or a parking lot.
- Your photo ID and the vehicle's title or registration, because ownership is checked before any key is programmed.
You hear the price on the phone before we set out, and if the car turns out to need something different, the new price comes before any extra work. If a child or pet is locked inside the vehicle, call 911 first.