The most common reason is that the battery has died. Attempting to replace the key fob battery is easy and cheap. It can be done with basic tools and with no automotive knowledge. Give replacing your key fob battery a go before having to take the vehicle in for a diagnosis and service, which can be pricey and leave you out of a car for days.
Common causes of a bad key fob/keyless entry remote:
- The battery in the remote has died
- The remote has failed, oftentimes due to wear or moisture
- The fuse in the vehicle for the remote system has blown
- The keyless entry system module or wiring has failed or malfunctioned
What you will need
- Use a plastic opening pry tool or flathead screwdriver to pry between the seams of the key fob. When using a screwdriver, use a plastic tool rather than a metal one to avoid scratching the plastic. Pry apart the key fob by twisting the small seam. Workaround the seams until the key fob separates.
- Once the fob is apart, the battery is exposed. Pry up on the end of the battery that is not held down by the two plastic tabs. Then, pull the battery out.
- Make sure the metal contacts where the battery touches have plenty of spring and are not worn flat due to use. If necessary, carefully pull the metal tab to bring it forward, so it makes better contact with the battery.
- Replace the battery with the correct one. In this case, it is a cr2032 coin battery. Slide the battery into the two plastic tabs that hold the top of the battery down, and then push down to secure it. Be careful and do it in this order. Pushing the battery down on top of the plastic tabs can break them and the battery will no longer be able to stay in place.
- Replace the back casing of the key fob back in place. Make sure the rubber seal is still in its correct place and not damaged. This rubber seal helps prevent water or moisture from entering the intricate electrical circuit board inside the key. Press the casing back into place and work around the entire key until it is completely snapped in place and back together.
- Test to make sure the key fob is now working, you are done!
All Mitsubishi models include Galant, Lancer Evo, Outlander, Eclipse, Mirage, and more. All year models including current-gen: 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, and 2021.
I replaced my key fob. Do I need to have it programmed at the dealer?
The short answer is yes. A new remote will need to be reprogrammed. Usually, due to restrictions on the software used for reprogramming these vehicle's computers, the car will also have to be taken to a dealer. However, aftermarket software and professional tools do exist that may be able to perform these functions.