If your vehicle has a keyless entry system, and the fob isn't working, you may need to call an automotive locksmith for help. Before doing this, there are a few things you can try to see if you can get the fob working again on your own. The first thing to try is to hold the lock button and the open button at the same time for about a minute. This is supposed to reset the locking system. If the lights in the car flick on and then off, or your horn beeps, the reset has worked. If it doesn't work, here are some other things you can try before calling in an automotive locksmith.
Change the Batteries
This may seem obvious, but because most people expect their fobs to work automatically, they never think about the batteries, which do need to be changed occasionally. While you can't do this with all types of fobs without taking them to locksmith or the dealership, some are made so you can easily open them and change the batteries. The other method involves grounding the transmitter wire, which is something that should be done by an experienced automotive locksmith.
Check the Spare Fob
The problem may not be with the fob itself, but actually in the receiver for the keyless entry system. Use your spare fob to try and unlock the car doors. If it works, then you know the problem was with the fob. If it doesn't work, you will need to have the receiver repaired by an automotive locksmith.
Turn the Vehicle On and Off Several Times
Another way to get your fob working again is to turn the key in the ignition on and off several times in a few seconds. This will tell the security system to enter the programming mode. Once you have done this, press any button on the fob, and it will sync back up the security system and it should start working again. If you have more than one fob, test each one to make sure that they are all in sync with the receiver.
Use the Manual Key
While many newer vehicles only have keyless entry systems, there are some models that do have both keyless and keyed systems. If you have a dual system, and nothing you have tried will make the fob work, you are just going to have to use the manual system until you can get an automotive locksmith to fix the problem and get your fobs working again.
If you're still stuck contact companies such as Oakleigh Locksmiths for help.