A key fob is a small remote control that can unlock your vehicle’s doors, open the trunk, and start the vehicle. This device might seem simple, but it’s a little more complicated than your TV’s remote control. In this article, we’ll discuss what you should know when your key fob runs out of battery.
A modern key fob has a radio frequency identification (RFID) chip and an antenna inside. When pressed, the antenna transmits radio frequencies that the vehicle’s reader device picks up.
A key fob transmits specific RFID tag information that matches the vehicle’s reader device. The reader device will only unlock the door if it receives the correct information, preventing other key fobs from unlocking the vehicle.
The RFID key fobs can also be programmed to transmit different vehicle commands, like opening doors or starting the engine.
A key fob has a coil cell battery that can deplete over time, which will weaken the key fob’s radio signals. When this happens, your vehicle might not pick up the signals right away.
You might need to press the button several times before the vehicle locks or unlocks. Pressing the key fob when you’re closer to your vehicle might help.
When the key fob battery is low, you might not be able to unlock your vehicle, which is the system’s major drawback. Fortunately, many key fobs come with an emergency blade, which is a traditional key hidden in the key fob.
Some keys are hidden in the key fob like a switchblade, while others lie behind a plastic cover. Some automakers put the emergency blade inside the key fob assembly itself, and you’ll need to pry the key open to access it.
Some vehicles have a start/stop button instead of an ignition switch. They detect the key’s presence using radio signals. However, a dead key fob won’t be able to send these signals. You might be able to unlock your car with the emergency blade, but how do you start the vehicle?
In this case, use the key fob to press the stop/start button instead of your finger. Your vehicle can detect the magnetic transponder, starting the engine. Once you have your vehicle started, you should try to replace your vehicle’s battery as soon as possible.
The battery for a key fob is usually a CR2032 coin cell battery. However, it can vary depending on your vehicle’s year, make, and model. This small battery can last around three to six years.
Some owners have reported that their vehicle’s key fob battery has lasted decades, while others have complained that their key fob runs out of battery in a few months. These are typically outliers, as key fob batteries typically last years.
Changing the key fob battery is simple. You don’t need to go to your trusted mechanic or dealership. To access the battery in the key fob, you’ll either need a flathead screwdriver or just a sharp fingernail.
Key fobs are opened by gently prying the plastic cover. Once opened, you’ll either see the battery readily exposed or behind a circuit board.
The place where you’ll need to pry will vary depending on the key fob’s design. Many key fobs have a small notch that you can pry. You can check your vehicle owner’s manual for specific instructions on replacing the key fob battery.
Remember to only use your key fob’s prescribed battery. Putting in a stronger battery can damage the circuitry.
It can be a good idea to have a spare battery inside your vehicle in case the key fob battery needs replacement. This can be quite useful, especially if you have a key fob that doesn’t have an emergency blade. Regardless of whether your key has an emergency blade, it’s best to replace the battery as soon as you notice weak key fob battery symptoms.
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