How to Repair a Remote Key
Even though most remote key fobs come with impressive battery life, they will eventually get worn out. Sometimes it's as simple as replacing the batteries, but occasionally there are more serious problems.
A quick fix that can help is dismantling the remote, cleaning the buttons and stretching them out and in. These techniques might be all you need to get your key fob to work.
Battery
If the fob is still functioning, you can swap out the CR2025 or CR2032 battery. If lowest price isn't then you can remove the fob and inspect the battery terminals and buttons for any indication of looseness or damaged parts. The terminals and buttons can be soldered back in place, but you'll need to be aware of the type of battery the fob is using.
If the battery isn't the issue you can try a backup key fob to determine whether you can unlock or start your car using it. If it's possible then it's time to replace your primary fob. If it's not require replacement, you'll need to have a professional inspect it to determine the problem. It could be as simple as reprogramming it, or require other repairs. You may also find that your vehicle has lost the fob. This is not something you can do on your own.
Case
The case of remote keys is the plastic housing that covers the outside and typically comes with the button pad that is replaced. It is recommended to purchase the latest case because the one you have case is likely to be quite dirty. Also, it is crucial that the circuit board in the case is correctly placed. The circuit board is responsible for the function of the key fob and can be tested with a normal multimeter by setting it to the RF (radio frequency) mode and holding a scanner tuned to the same frequency the key fob operates on close to it, and listening for signals that pulsate upon button presses.
Check the contact points of the buttons on the keypad. They may be loose over time or broken. By carefully re-soldering them back into their original position can usually restore them to their original function unless they break completely.
Buttons
If your key fob buttons aren't working or are difficult to press, you can buy an alternative dorman or Motormite remote key housing online at an affordable cost for the model/year/make. Then pop the circuit board out of your old case into the new one. In some cases it may be necessary to adjust the position of the board slightly. Then, you can use aluminum foil and double-sided tape to stick to the black contact points on the buttons.
Programming
The key fob and receiver in your car are paired, but this connection can be corrupted. A professional will examine the vehicle to determine the make, year and model and use specialist equipment to re-pair or program a blank fob or transponder chip (or duplicate a key should this be possible). Then they test the remote to be sure it functions.
It is crucial to be cautious when programming a blank key, as the process is often complicated and different manufacturers require certain steps that are slightly different. It is also easy to skip a step or delay too long before leaving the programming mode, which is why it is best to use professionals with extensive knowledge of the security system of your vehicle to avoid damaging your car. Certain programming tools can also be capable of reading diagnostic trouble codes from your vehicle, which could help repair or troubleshoot additional problems.