720 499 7737What is A Key Fob?
Updated on 3.31.2025
What is a key fob? As the automotive industry continues to evolve, it is constantly driven by new technologies. That includes the technology that allows drivers to lock and unlock their cars, as well as start their ignition systems without a key.
While metal keys are still used to access a car’s security features, very seldom is a metal key used without some other kind of complementary device. In many cases, the complementary device of choice is a car key fob device.
The following information will hopefully teach you everything you need to know about fob devices and maybe more.
Why is It Called a Key Fob?
What does a fob stand for with keys? Contrary to popular belief, the term “fob” is not an acronym. It’s actually a word that means pocket, which was derived from the German word “fuppe.” In the case of a car key fob, it would represent an automotive device that is small enough for a driver to carry in their pocket.
As for the device itself, it is typically contained inside a small durable plastic casing. Inside the casing are a cellular battery, an RFID chip, and an internal antenna. On the outside, the casing has several buttons. There could be anywhere from 2-4 buttons on a given fob. Each of the buttons will perform a particular action when pressed. The four most common functions are:
- Unlocking car doors
- Locking car doors
- Unlocking the trunk
- Initiating the ignition switch to start the car
Note: Other functions might be available depending on the vehicle in question. A programmable key fob offers users some flexibility as they can actually program each button to perform a certain function.
Not all fobs will have the car ignition button. However, it is becoming far more common with each passing year as car manufacturers try to minimize the need for traditional metal car keys.
What Does a Key Fob Look Like?
Curious about what a key fob looks like? At Denver Locksmiths, we’re here to unlock the mystery! A key fob is a small, handheld device—often sleek and rectangular, sometimes with a few buttons—that remotely controls your car’s locks, trunk, or even ignition. Think of it as your vehicle’s trusty sidekick! Designs vary: some are compact with built-in keys, others are high-tech with LED displays.
Types of Key Fobs
Fob devices can be used as a security feature for a variety of vehicles. That would include cars, vans, trucks, motorcycles, and even boats. Residential key fobs are also available for homeowners who are seeking a more secure way to protect their homes.
Note: Car and truck fobs date back as far as 35 years. Before that, traditional locks and metal keys were the only alternative, though transponder keys were popping up here and there.
How Do Key Fobs Work?
Once you understand what is a key fob, your curiosity should prompt you to ask the question, “How does a key fob work?”
Key fob definition starts with the key fob buttons, a chip, and an antenna. When one is pressed, it sends a radio signal through the fob’s RFID chip and an internal antenna to a receiving RFID chip and an internal antenna that is located in the car’s onboard computer. If the signal that is sent to the receiving chip or reader matches what has been programmed, the function will be performed as requested. Herein lies the security feature that keeps intruders from being able to access a particular car.
Benefits/Advantages Derived From Key Fobs
What does a key fob do? In the automotive world, fob devices are often considered one of the industry’s great innovations. Why? It has everything to do with the benefits or advantages car owners get from using a fob as opposed to relying on traditional metal keys. Here are some of the benefits or advantages that innovators had in mind when they invented the fob:
- Fob devices are often more durable than traditional metal keys
- Indruders find it more difficult to access cars that operate with fobs
- Reduces the need for multiple keys – locks & ignition
- Fobs are easy to replace and new fobs are easy to program
- Customizable fobs can offer extra layers of security – access can be restricted by location and time/day
- Fob cellular batteries have long lives – multiple years
- Fobs make it easy to unlock doors when hands are full – suitable for disabled persons
Denver Locksmiths – About Our Key Fob Services
Since fobs offer a lot in the way of convenience, they are relatively easy for users to maintain. For instance, changing a cellular battery only requires performing these three (3) tasks:
1. Locate and purchase the correct battery replacement. This information should be available in the car’s owner’s manual or on the car manufacturer’s website.
2. Remove the back of the fob casing, remove the old battery, and insert the new battery with the positive (+) pointing in the right direction.
3. Reattach the back of the casing and test to make sure everything is operating properly.
As for repairing and programming a fob device, that’s where things could get a little complicated. Instead of wasting time and trying to handle these tasks on your own, your time and effort might be better spent by contacting a professional locksmith like Denver Locksmiths.
We employ a terrific team of well-trained locksmith technicians to handle issues related to car key fob devices. The fob-related services we can provide include:
- Repair of fob devices and reprogramming
- Battery replacements
- Replacement of fob devices with the appropriate programming
- Assistance with programming customization
Why Choose Denver Locksmiths
Denver Locksmiths has been serving as a full-service locksmith in the Denver region for years. We employ a great team of locksmith technicians who fully understand the service needs of their Colorado neighbors.
Our full menu of locksmith services covers residential properties, Airbnb rentals, retail and commercial businesses, and motorized vehicles. Our comprehensive list of services includes:
Note: All of these services and more are available as emergency services 24/7/365. We respond to most calls in 30 minutes or less.
Need more reasons to call Denver Locksmiths? We offer great customer service with a smile. Our prices are always fair and affordable. We stand by our work with a nice 100% customer satisfaction guarantee. Finally, we want your business now and in the future.
The next time you need a professional locksmith to handle a fob device issue or a problem with a lock or key, give us a call. We are confident you will appreciate our service so much that you’ll put us first on your speed dial.
Frequently Asked Questions
How far can a car key fob work from my car?
Range varies—think 10 to 100 feet, depending on your fob and Denver’s quirks. Basic models might tap out at 20 feet, while high-end ones stretch further (handy for spotting your car at DIA’s massive lots). Walls, cold weather, or interference from LoDo’s Wi-Fi jungle can shrink that distance. If yours feels weak, it might need a battery swap—or a pro check from [Company Name]. We’ll get that signal zinging again!
Why do some car key fobs start the engine?
Welcome to the future, Denver drivers! Remote-start fobs are like a warm hug on a snowy morning. They work the same way—radio signals—but talk to your car’s ignition system too. Press the button, and your engine fires up while you sip coffee inside. Perfect for defrosting near Cherry Creek or pre-cooling after a hot Red Rocks show. If your fob’s slacking on this trick, Denver Locksmiths can reprogram or upgrade it, stat.
How does a key fob know it’s my car?
It’s all about the secret handshake—well, a digital one. Every key fob has a unique code baked into its signal, like a password. Your car’s computer checks it against its own list. Match? You’re in. No match? Tough luck, buddy. That’s why stealing a fob doesn’t always work without cracking the code—a security perk for Denverites parking downtown. If your fob’s code goes haywire, our techs at Denver Locksmiths sync it up fast.
What happens if my car key fob stops working?
Cue the mini meltdown—especially if you’re stranded at a trailhead near Morrison. If it quits, try the basics: swap the battery (usually a CR2032 from any Denver gas station) or use the hidden key inside. Still nada? Could be a dead fob, a car glitch, or Denver’s weather messing with the signal. Don’t sweat it—Denver Locksmiths races out 24/7 with mobile locksmith magic to replace or reprogram it on the spot.
