Check the new battery first
When a fob stops working right after a battery swap, the new battery is the first suspect. A weak battery straight from the package, the wrong size, or one installed upside down will all leave the fob dead. Confirm you used the correct coin cell type and that the plus and minus sides match the markings inside the fob.
Fingerprints and skin oils on a coin battery can also reduce contact over time. Handle the new cell by the edges, wipe it clean, and make sure it snaps in firmly so the contacts press tightly against it.
Reassembly and contact issues
It is easy to bend a metal contact or fail to seat the two halves of the fob fully during reassembly. Open the fob back up and check that the internal contacts are not bent flat and that the case clicks completely shut. A loose case can let the battery shift and lose contact while you drive.
If the buttons feel dead but the hidden emergency blade still works in the door, the electronics may simply not be getting power. Re-cleaning the contacts and reseating the battery solves many of these cases.
When reprogramming or a new fob is needed
On most vehicles a battery change does not erase programming, so a fob that worked before should work again once power is restored. If the contacts are fine and a known-good battery still leaves it dead, the fob board may have failed, sometimes from age or moisture.
A mobile locksmith can test the fob, replace it if needed, and program the replacement to your car on site. Call us with your year, make, and model and we will confirm whether a quick fix or a new fob is the answer.
Still have a key or fob question?
Tell us your year, make, and model and we will confirm exactly what your vehicle needs before we head out.