In case of severe interference, the remote may not work at all. The remote key may work when you’re near the vehicle, but may not work from a distance. Optima remote control signal can be disrupted by objects, poor weather conditions or transmitters on the same frequency band close to the vehicle. If the 12 volt battery is dead or if the electric current has been interrupted due to corrosion on the battery terminals or the ground connection, all on-board electronics will stop working. The remote keyless system and the central locking system in Optima require the 12 volt battery to be in healthy state to function properly.

If the key fob still doesn’t work after cleaning and drying, the chip is probably fried and you will have to buy a new key.

In case of exposure to salt water, or soapy or dirty water, it is recommended to clean the chip with isopropyl alcohol or electronic cleaner. If your Optima key fob stopping working after exposure to clean tap water or rain, immediately remove the battery and clean the electronic component with paper towel and let it dry fully before putting back the battery. Exposure to excessive water increases the risk of water damage, so you shouldn’t make this a habit. If your Optima key fob survived a wash cycle, or a deep bath in the ocean or pool water, it doesn’t make the key fob waterproof, it means you got lucky. Submerging the key in ocean water at the beach can be much more damaging to key fob electronics due to highly conductive nature of salt water. A splash of water or brief exposure to light rain should be fine, but exposure to excessive amount of water like submerging the key in the pool can cause the water to penetrate the seals and damage the chip. Your Optima key has rubber seals which prevents the water from getting to the electronic chip inside. If your Kia Optima key fob has taken a bath in the soapy water of the washing machine after you forgot to take it out of your pants pocket, water damage is very likely. Also make sure all the battery contacts are corrosion and dust free.

Make sure the battery is firmly placed and does not move around when you shake the remote. If the clips don’t have any tension, it can cause contact issues and the remote may not receive any power. The battery inside the key fob of Optima has metal retaining clips that hold the battery in position and completes the circuit. This is assuming the new battery you installed is healthy and its use by date is many years away. Depending on how often you use the key fob or remote control of your Optima, the battery should last between two and four years.

2016 kia optima battery