How to Repair a Remote Key
Even though most remote key fobs boast amazing battery lifespan, they eventually degrade. Sometimes it's as simple as changing the batteries, however sometimes there are more serious problems.
An easy fix that could help is dismantling the remote, cleaning the buttons and flexing them in and out. These techniques might be all you need to get your key fob to work.
Battery
If the fob is working, you can swap out the CR2025 or CR2032 battery. If not, you can open the fob and inspect the battery terminals and buttons to look for signs of wear or broken parts. Most of the time, the buttons and terminals can be re-soldered back into place but you'll need be aware of the type of battery is used by your fob.
If the battery isn't the issue Try using a backup key fob to determine whether you can start or unlock your vehicle with it. If you are able to do so, it's time for a replacement of the primary fob. If not, a professional check is necessary to determine the reason it's not working correctly. It could be a simple reconfiguration, or it may require other types of repairs. You may also find that your car has lost the fob. This isn't something you can tackle on your own.
Case
The outer plastic housing of a remote is referred to as the case. It is usually equipped with an alternative button pad. It is essential to choose an entirely new case since the original will probably be quite dirty, and it is essential that the circuit board is placed correctly in the case. The circuit board controls the key fob's function. You can test it with a multimeter set to RF (radiofrequency) mode and a radio scanner that is tuned to the same frequency as the key fob.
Examine the contact points of the buttons on the keypad. They could be loose over time, or even broken. Soldering them back in place can often restore them to full function, except if they snap completely.
Buttons
If the buttons on your key fob aren't working or are difficult to push, you can purchase an alternative dorman or Motormite remote key housing online for the lowest price for your model/year/make. Then, take the circuit board out of the old case and insert it into the new one. You may have to slightly alter the position of the circuit board for certain models. You can then apply aluminum foil with double sided tape to adhere to the black contact points on the buttons.
Programming
The key fob is paired with the receiver in your vehicle, and this connection could be damaged. A professional will assess the vehicle to determine the make, year and model and use specialist equipment to re-pair or program an empty fob or transponder chip (or make a key replica if this is possible). Then they test the remote to be sure that it works.
It is essential to be careful when reprogramming the blank key, because the process is often complicated and different brands require distinct steps. It is also easy to skip a step or delay too long before leaving the programming mode, therefore it is recommended to hire an expert with a thorough understanding of the security system of your vehicle to avoid damaging the car. Some key programming tools can also read diagnostic trouble codes in your vehicle. This Web page can help you solve other issues.