A key fob that works only sometimes, or not at all, can leave you using the key in the door like it is 1995. In most cases the cause is minor.
Start with the easy things
- Flat fob battery. The most common reason. A short range or having to press several times is the usual first sign. Replace the coin battery.
- Dirty or worn buttons. Buttons can stop making contact after years of use.
- Signal interference. Strong radio signals near some parking areas can block the remote briefly. Try moving closer or trying elsewhere.
When the fob still does not work
- Fob lost its programming. This can happen after a battery change or a flat car battery. It can often be re-programmed.
- Weak car battery. A tired battery in the car can stop the receiver working properly.
- Faulty receiver or wiring. If a spare fob works and the first one does not, the fob is the problem. If neither works, the fault is in the car.
- Damaged fob. Water damage or a drop can crack the circuit board inside.
A useful test
Try your spare key fob. If it works, the problem is with the first fob. If neither works, the car side needs checking, and an electrical test will find the cause quickly. Keep the spare somewhere safe, because having only one key makes any repair more expensive.