How to Protect Your Car Key Fob from Relay Attacks

25.04.2025

Car theft has entered the digital age — and unfortunately, so have the thieves. As car manufacturers move toward keyless technology, a new type of threat has emerged: the relay attack. Unlike traditional break-ins, this high-tech method allows criminals to steal a vehicle without touching the keys — or even breaking a window.

Imagine this: your car is parked safely outside your house. Your key fob is inside, hanging on a hook by the front door. You're fast asleep. But outside, two individuals with small electronic devices are working together. One stands near your front door, scanning for a signal from your key fob. The other waits by your car. Within seconds, your key’s signal is captured, extended, and transmitted to your car. It unlocks, starts, and drives away — and you might not notice until morning.

This is not science fiction. It's called a relay attack, and it's one of the fastest-growing vehicle theft methods worldwide.

Why Relay Attacks Are So Effective

The key to this technique is exploiting the constant communication between your car and its fob. Most keyless entry systems are designed for convenience — you don’t even need to press a button. The car automatically detects the presence of the key fob and unlocks when you approach.

This convenience is exactly what makes it vulnerable. Relay devices — which are cheap, portable, and easy to use — can mimic the signal and trick the car into thinking the key is nearby, even when it’s inside your home.

Security experts have raised the alarm about this method for years, but many drivers still don’t realize how easily their vehicles can be accessed. In the UK alone, keyless car theft now accounts for more than 90% of vehicle thefts involving high-end models, according to the AA. And with the rise of online tutorials and black-market tools, the problem is growing globally.

So, What Can You Do to Stay Safe?

Fortunately, protecting your vehicle doesn’t require advanced tech or a huge investment — just awareness and a few smart habits.

One of the most effective ways to block relay attacks is also the simplest: store your keys in a signal-blocking container. Often called a Faraday pouch or Faraday box, this lined case prevents radio signals from escaping. When your keys are stored inside, they can’t be scanned or cloned, no matter how close a thief gets to your home.

Placement also matters. Many drivers leave their keys near the front door or on an entryway table — spots that are easy to access from outside. Moving your keys to the center of your home, an upper floor, or even a metal box can reduce signal exposure dramatically.

Some newer key fobs allow you to manually disable the signal when it’s not in use. This feature is often hidden in the manual and rarely mentioned by dealers. Taking a moment to learn whether your key supports this — and how to activate it — can make a big difference.

It’s also worth checking whether your vehicle’s software is up to date. Many automakers periodically release firmware updates that strengthen encryption or reduce signal range. In some cases, updates can even detect and block suspicious unlock attempts.

And while it may seem old-fashioned, physical security still works. Devices like steering wheel locks or gear shift immobilisers can be powerful visual deterrents. Even if a thief manages to unlock your vehicle, the sight of a bulky lock inside may be enough to send them looking for an easier target.

If you're looking for practical solutions beyond GPS, check out our blog: Do Car Keys Have GPS? What You Need to Know About Key Tracking.

In summary, here are a few key takeaways to keep your keys and vehicle safer:

Store your fob in a signal-blocking pouch or metal container

Keep keys away from entry points like doors or windows

Disable keyless signals if your fob supports it

Update your car’s firmware regularly

Use visible anti-theft devices as a deterrent

Looking Ahead: Smarter Cars, Smarter Drivers

Relay attacks are part of a larger trend — one where modern technology makes life more convenient, but also creates new risks. Just like we’ve learned to secure our phones and passwords, we now need to think about how we secure our vehicles.

As carmakers explore more secure solutions — like Ultra Wideband (UWB) tech and biometric verification — drivers still need to take responsibility for their vehicle’s safety. The tools are already out there, and many of them cost less than a meal out. It’s not just about avoiding theft; it’s about peace of mind.

So next time you get home, before tossing your keys on the hallway table, take a second to think: are they really safe there?

31.03.2025

How to Program a Spare Car Key: Should You DIY or Call a Pro?

You’ve got a spare car key in your hand and one big question on your mind: can you program it yourself, or should you visit a locksmith or dealer? The answer depends on your car and the key. In this guide, you'll discover when DIY programming is possible, when it's not, and how to avoid common mistakes. Whether you're aiming to save money or just want a backup key for peace of mind, here's everything you need to know. Types of Car Keys: What You’re Working With Not all car keys are the same—and that matters. Older vehicles often use simple metal keys or basic transponder keys, while modern cars rely on electronic fobs and smart keys with encrypted chips. If your car was built before the early 2000s, there’s a good chance you can program a spare yourself without any special tools. Newer vehicles, however, might require dealer-level software or diagnostic equipment to complete the job. Basic key types include: Non-transponder metal keys : can be copied at any key-cutting service. Transponder keys : contain a chip that communicates with your car’s immobilizer. Remote key fobs : combine keyless entry with a transponder chip. Smart/proximity keys : high-tech, often require dealer programming. How DIY Key Programming Works If your car supports on-board programming, you're in luck. Here’s how a common DIY method looks: Insert your original (master) key into the ignition and turn it to “on” (don’t start the engine). Leave it for five seconds, then remove it. Quickly insert the new spare key and turn it to “on.” Wait for the security light to blink or turn off—this confirms successful programming. Test the spare key by starting the engine. Note: This process varies by vehicle. Always consult your owner's manual or search for your specific make, model, and year online before starting. When You’ll Need a Professional DIY isn’t always an option. If your car uses advanced keyless systems, push-button start, or encrypted communication, programming usually requires access to manufacturer software and security codes. In these cases, a qualified locksmith or dealership is your best (and safest) bet. Also, if your vehicle requires a unique PIN to program a new key—and you don’t have it—don’t guess. Incorrect attempts could lock the system and result in costly reprogramming. Choosing the Right Spare Key Buying the correct spare key is critical for success. You’ll need: The correct transponder chip type (e.g., ID46, ID48, PCF7946 ) Matching blade shape or key profile The correct frequency (commonly 433MHz or 868MHz ) Avoid cheap generic blanks unless you're certain they’re compatible. Poor-quality keys may not accept programming or may fail shortly after. Quick DIY Checklist: Are You Ready? You already have a working master key Your vehicle supports on-board key programming The spare matches in chip, frequency, and blade You’re comfortable following time-sensitive steps You’re okay calling a pro if things don’t work If you checked most of those, DIY might be a great fit. If not, you’re better off with professional help—it could save you time, frustration, and possibly money in the long run. Be Smart with Your Spare Key Having a backup key is more than convenient—it’s essential. From lost keys to unexpected lockouts, a properly programmed spare key can save the day. If your vehicle allows DIY programming, take your time, follow instructions carefully, and double-check compatibility. If you hit a wall, don’t force it. Pros are there for a reason. No matter which route you take, you’ll thank yourself later for being prepared. Because when it comes to your car keys, one really isn’t enough.

12.06.2025

The Ultimate Guide to Opel, Peugeot, and Citroën Car Keys: Battery Replacement, Flip Key Issues, and Shell Compatibility

Car keys have come a long way from simple metal tools to advanced electronic devices. While they offer convenience and security, they're also prone to wear and tear over time. If you own an Opel, Peugeot, or Citroën, you've likely encountered a dead battery, faulty buttons, or a cracked key shell. These issues, though frustrating, are easy to fix with the right approach. This guide explores everything you need to know to maintain or restore your car key's functionality—without unnecessary expense. From understanding how these keys work, to step-by-step maintenance practices, we'll walk you through all the essentials to keep your keys working like new. How Car Keys Work Today Modern car keys are more than just tools to unlock and start your vehicle. They are miniaturized computers embedded with microchips, transponders, and signal systems that communicate with your car's onboard electronics. Most Opel, Peugeot, and Citroën models feature flip keys with integrated remote buttons, and inside each key fob lies a delicate configuration of electronics that perform critical functions like remote unlocking and engine ignition authorization. These keys depend heavily on power from a small coin-cell battery, usually the CR2032. While small and seemingly insignificant, the battery is the heart of your key fob. When it begins to fail, even slightly, the symptoms can range from reduced signal range to complete unresponsiveness. That’s why it’s crucial to replace it in time. Replacing the Battery in Opel Car Keys Your Opel car key is essential to your daily routine. Over time, the lithium CR2032 battery inside may weaken, resulting in slower response or reduced range. The good news is that replacing it is straightforward and requires only a few tools. Once you identify your key type—typically a flip key with two or three buttons—you can open the casing using a small screwdriver or plastic tool. Inside, you'll find a battery nestled within the key's internal framework. Carefully remove the old battery and insert a new CR2032, ideally a reliable model like the Panasonic CR2032 . Proper alignment is crucial; the wrong orientation can prevent the key from functioning entirely. Align the shell halves carefully and press them back together until they click into place. If your key shell is also showing signs of damage or wear, consider replacing it with this Opel 3-button key housing . Replacing the battery is a quick job, but it makes a world of difference in reliability and peace of mind. Plus, it spares you the inconvenience of getting stranded or needing dealer intervention. Common Peugeot Flip Key Issues and How to Fix Them Peugeot flip keys are compact and stylish, but frequent use can expose a few recurring problems. The flip mechanism may lose tension, buttons may stop responding, or the outer shell may crack. In many cases, the spring inside wears down, and the plastic buttons may degrade over time. Exposure to moisture, dirt, or accidental drops can also damage the key fob. These symptoms can often be resolved by replacing both the battery and the key shell. Thankfully, most replacement shells come with a new flip mechanism already installed, making the process quick and cost-effective. If you're dealing with a damaged shell or non-functional buttons, a compatible Peugeot key shell can restore both the look and performance of your key. To repair your key, begin by opening the shell using a thin screwdriver. Remove the internal circuit board and transponder chip carefully. Transfer them into the new shell, ensuring everything fits snugly. Insert a fresh CR2032 battery before closing the key shell, then test all functions. Unlike dealer replacements, this DIY approach is affordable and efficient, putting the control in your hands. Understanding Citroën Key Shell Compatibility Citroën keys often resemble Peugeot models but feature subtle design differences that can impact shell compatibility. Before purchasing a replacement shell, it's important to examine a few key details. First, confirm that the button layout matches exactly—some models include a trunk release, while others do not. Next, check the blade type, usually HU83 or VA2, and make sure your new shell supports that configuration. You’ll also need to ensure there’s a space for the transponder chip, as without it, your car won’t start. Lastly, confirm that your circuit board (PCB) fits securely in the new housing. If you're unsure, compare your key with this Citroën 3-button shell for reference. A mismatched shell can result in poor fitment, misaligned buttons, or failure to lock and unlock your car. That’s why it's important to compare your current key closely to any replacement product. Shell replacements are not one-size-fits-all—small deviations in size or design can render them useless. Going Beyond: Caring for Your Car Key Long-Term Maintaining your car key goes beyond occasional repairs. Think of it as part of your overall vehicle care routine. Keep your key clean by regularly wiping it down with a soft cloth. Avoid exposing it to moisture or extreme temperatures, which can damage the battery and internal electronics. If your key starts to feel loose or if the blade no longer flips smoothly, it's a sign that maintenance is due. Another often-overlooked aspect is the condition of your key ring. Overloaded or heavy keychains can put unnecessary strain on the ignition switch and the key’s blade over time. Keeping your key light and secure can prolong both the key and the ignition system’s lifespan. If you find yourself frequently pressing buttons or experiencing lag in signal response, don't ignore it. These early symptoms are usually signs that a new battery is needed, or the shell's contacts are worn. Addressing small problems before they escalate can save you from full key failure. Car Key Maintenance Caring for your car key doesn’t have to be a daunting task. Whether you drive an Opel, a Peugeot, or a Citroën, regular maintenance and minor DIY repairs can significantly extend the life of your key. Replacing a worn battery and upgrading a broken shell not only restores functionality but also revives the overall appearance of your key. Use quality components, take your time during repairs, and always test your key before final assembly. By taking these small steps, you can avoid costly replacements and enjoy reliable key performance for years to come. Explore trusted replacement parts and accessories online at mr-key.com to keep your car keys in top condition year-round.

19.06.2025

How Hot Weather Can Damage Your Car Key Fob – And What You Can Do About It

When you think about how hot weather affects your vehicle, your first thoughts might go to the engine, the tires, or maybe even the air conditioning. But there’s one small, essential part of your daily driving routine that’s often overlooked — your car key fob. It might seem like a tough little device, but the truth is, it’s far more sensitive than it looks. If you’ve ever left your key fob on the dashboard, in a hot glove box, or even inside your pocket during a heatwave, you may have already caused damage without realizing it. Car key fobs are built with delicate electronics, plastic shells, and lithium coin batteries — all of which are vulnerable to extreme temperatures. In this article, you’ll learn how hot weather affects each part of your key fob, how to spot the early signs of damage, and most importantly, what you can do to protect it. Taking just a few simple steps can save you from the cost and inconvenience of a non-functioning remote, especially when you least expect it. The Plastic Shell: First to Feel the Heat One of the first things to suffer from heat exposure is the plastic casing that protects your key fob. While it’s designed to withstand everyday use — being dropped, tossed in a bag, or handled frequently — it’s not built to survive hours in a baking-hot car. The interior temperature of a parked vehicle can soar past 60 or even 70 degrees Celsius on a sunny day, especially if the key is sitting directly in sunlight. Over time, this level of heat can soften the plastic, causing it to warp, bend, or even split at the seams. You may start to notice that your key doesn’t close as tightly as it used to, or the buttons may feel soft and spongy instead of firm. Cracks might appear along the sides, or parts of the shell may become discolored. While this might seem like a cosmetic issue at first, it has serious implications — a compromised shell allows moisture, dust, and debris to enter the fob, putting the internal electronics at risk. If your key fob’s shell is already showing signs of wear, especially after a hot summer, it’s time to consider replacing the casing before the damage gets worse. Battery Breakdown: How Heat Drains Power Inside your key fob, there’s usually a small lithium battery — typically a CR2032 coin cell. These batteries are reliable under normal conditions, but they don’t respond well to high temperatures. In fact, exposure to extreme heat can accelerate chemical breakdown inside the battery, leading to faster discharge and a shorter overall lifespan. What’s worse, in severe cases, the battery can swell or leak, which can damage the internal components of your fob permanently. If you’ve ever noticed your key fob suddenly stops working or becomes unreliable during the summer, there’s a good chance the battery is struggling under heat stress. The signal may become weaker, you might have to press buttons multiple times, or the remote might stop responding altogether. Replacing the battery is a quick and inexpensive fix, but it’s important to recognize that battery issues are often just the first symptom of deeper heat-related problems. Internal Electronics: Silent Victims of the Heat While the shell and battery are easier to see and replace, the most serious damage often happens silently — deep inside the electronic circuit board. This board, often referred to as the platine, is responsible for all communication between your key and your vehicle. It’s a compact, delicate system of soldered connections and microchips, and unfortunately, it’s not designed to cope with repeated thermal stress. When your key fob is exposed to fluctuating high temperatures, the constant expansion and contraction of materials can loosen solder joints or weaken connections. Moisture that gets trapped inside the shell during humid summer months can accelerate corrosion, especially if the casing is already cracked or loose. The damage might not be immediate, but over time you may find that your key fob becomes unpredictable — sometimes it works, other times it doesn’t, and eventually, it might stop working completely. What You Can Do to Prevent Heat Damage The good news is that most heat-related damage to key fobs is preventable with just a little care and awareness. First, never leave your key fob inside a parked car for extended periods, especially not in direct sunlight. It’s easy to toss your keys into the cup holder or leave them on the dashboard while you run errands, but those few minutes can expose them to dangerous levels of heat. Instead, keep your keys on you or store them in a shaded, temperature-controlled area. If you’re regularly in hot environments — such as driving in warm climates or working outdoors — consider investing in a protective silicone or leather cover. These not only shield the shell from heat exposure but also provide added protection against drops and dirt. You should also make it a habit to replace your battery once a year, even if it seems to be working fine. Batteries weakened by heat can fail suddenly, and a fresh cell ensures your key fob keeps working when you need it most. Finally, if your key fob’s shell is visibly worn or loose, replace it immediately. Many online stores, including Mr Key, offer affordable replacement shells that are easy to install and give your remote a like-new feel. Don’t wait for the damage to reach the internal electronics — by then, repair options are limited and usually more expensive. Protect Your Key, Protect Your Drive Your car key fob might be small, but it plays a huge role in your daily routine. From unlocking doors to starting your engine, it’s a modern convenience we all depend on — until it stops working. And while many drivers are careful with their car’s mechanical systems, few think twice about leaving their key fob in the heat. Now that you know how much damage summer temperatures can cause, you can take the steps needed to protect your key before it’s too late. If you’re looking for high-quality key shell replacements, batteries like the CR2032, or even complete key fobs compatible with your vehicle, Mr Key has you covered. Our online shop offers trusted parts for Peugeot, Citroën, Nissan, Suzuki, Fiat, and more — all designed to help you repair and maintain your car keys quickly and affordably.

06.11.2025

Can I order a replacement car key online with delivery?

Short answer: Yes. You can order a replacement car key online in the UK and have it delivered in 3–4 days. Choose the right key type, provide a photo or key code for cutting, and have a local locksmith program it when it arrives. Why trust this guide: With over 25 years in the locksmith trade and more than 650,000 satisfied customers, Mr-Key explains exactly how online key replacement works — clearly, securely, and step by step. When online replacement works (and when it doesn’t) Ordering online is ideal if you need a spare, a like-for-like remote, or a replacement for a lost or damaged key. It’s the fastest and most convenient way to get OEM-grade parts delivered to your door. You simply order the correct key, have it cut from a photo or key code, then let a local locksmith program it to your vehicle. Online ordering doesn’t replace immobiliser pairing. Modern vehicles still require professional programming once the key arrives. Key types explained Transponder keys These have a mechanical blade and an electronic chip that communicates with your car’s immobiliser. Remote fobs Include lock/unlock buttons plus a built-in transponder. We supply the pre-cut blade (if requested) and tested electronics. Proximity or smart keys Keyless entry and push-start units. Delivered ready for your locksmith to pair with the car. Key shells & batteries Replace worn housings or dead batteries without any programming. Also available: caravan keys, ATV keys , roof-rack keys , mailbox keys, towbar keys , and more. Browse our full range at mr-key.com . How online ordering works 1. Identify your key Use your vehicle make, model, and year. Match your key shape, button layout, and frequency markings. 2. Choose how to cut it By photo: send a clear image of your existing key. By key code: provide the manufacturer’s key code for factory-accurate cutting. 3. We cut and test Keys are machine-cut and tested for precision. Electronics are checked before dispatch. 4. Delivery in 3–4 days Typical UK delivery with tracking and updates. 5. Local programming Arrange a nearby automotive locksmith to pair the key. Most jobs take 15–30 minutes. What affects cost Key type — proximity and smart keys cost more than basic transponders. Electronics and frequency — differ by brand and year. Cutting method — photo or code; standard or laser blade. Programming complexity — varies by model. Extras — spare shells, emergency blades, or upgraded housings. Pro tip: Order two keys now — you’ll save money on future locksmith visits and prevent lockouts. Programming: DIY vs local locksmith Modern immobilisers are secure by design. Mr-Key does not supply pairing or programming kits. A professional locksmith uses diagnostic tools to safely program your new key and verify vehicle ownership. It’s faster, safer, and ensures full functionality. Shipping, warranty & returns Delivery: 3–4 days across the UK. Warranty: 12-month full coverage on keys and electronics. Returns: Contact support before programming — unused items are easier to exchange. Dealer vs local locksmith vs online Option Speed Convenience Programming Best for Main dealer Medium–slow Appointment required Dealer tools Brand-new cars, under warranty Local locksmith Fast Mobile visit Done on site Emergencies, quick help Online (Mr-Key) 3–4 days Order from home Done by locksmith Planned replacements, spares Most UK drivers choose online ordering + local locksmith pairing — the fastest, most cost-efficient combination. Troubleshooting after delivery Key turns but car won’t start Blade fits, but immobiliser isn’t paired yet. Book a locksmith. Remote buttons not working Replace the battery and re-pair during programming. Proximity key not detected Use the emergency start position (usually near the steering column) and ask your locksmith to register it. Blade feels rough Use light graphite lubricant or send a photo for recheck. How to avoid another lockout Order a second key and keep it at home. Replace weak remote batteries yearly. Label your spare with the vehicle reg. For keyless cars, store keys away from doors and use a signal-blocking pouch. FAQ Can I order a replacement car key online and get it delivered? Yes. Send your key photo or code, receive delivery in 3–4 days, and have it programmed locally. Do I need proof of ownership? Your locksmith may ask for it. For UK vehicle documentation, see GOV.UK – V5C log book . What’s the difference between key types? Transponder keys start the car; remote fobs add buttons; proximity keys enable keyless entry/start. Can you cut my key from a photo? Yes. Clear, well-lit images allow accurate decoding and cutting. Can I program the key myself? No. Only an automotive locksmith can safely pair it. How long does delivery take? Usually 3–4 days within the UK. Do you cover my vehicle? Almost all brands plus caravans, ATVs, lockers, and more. What warranty do I get? 12-month full warranty on all keys and electronics. What if the battery is dead? Replace it with the correct cell. If issues continue, have the locksmith check frequency and pairing. What if I’ve lost all keys? Order online and arrange programming. Mobile locksmiths can often attend on site. Can I order two keys? Yes — it’s the smartest option to prevent future emergencies. Shop now: https://mr-key.com

Cookie Name	Cookie Provider	Cookie Description	Life of the cookie	Cookie Type
XSRF-TOKEN	PHP	Ensures security for visitors by preventing cross-site request forgery. This cookie is essential for website and visitor security.	1 day	1st Party
laravel_session	PHP	To store the username of the logged in user. This information is necessary to allow the user to remain logged in to a website without having to submit their username and password for each page visited. Without this cookie, the user cannot move to areas of the website that require authenticated access.	Up to 2 hours	1st Party
__stripe_mid	Stripe	Serves to provide fraud prevention when attempting to shop on the site.	Up to 1 year	3rd Party

Cookie Name	Cookie Provider	Cookie Description	Life of the cookie	Cookie Type
_fbp	Facebook	This cookie is set by Facebook to deliver advertising when they are on Facebook or a digital platform powered by advertising on Facebook after you visit this website.	2 months	3rd Party
fr	Facebook	The cookie also tracks a user's web behavior on sites that have a Facebook pixel or Facebook social plugin.	-	3rd Party

Cookie Name	Cookie Provider	Cookie Description	Life of the cookie	Cookie Type
_ga	Google Analytics	Used to distinguish users (denied by default).	2 years	3rd Party
_gid	Google Analytics	Used to distinguish users.	24 hours	3rd Party
_gat	Google Analytics	Used to reduce the query rate. If Google Analytics is implemented via Google Tag Manager, this cookie will be named _dc_gtm_ .	1 minute	3rd Party
	Google Analytics	Contains campaign-related information about the user. Linked Google Analytics and Google Ads accounts, Google Ads website conversion tags will read this cookie.	90 days	3rd Party
Google Remarketing	Google Analytics	Used to track pages viewed by users that are sent to Google Ads	-	3rd Party
dynx_itemid	Google Analytics	Used to track product ID in Google Ads	-	3rd Party
dynx_pagetype	Google Analytics	Used to track page type in Google Ads	-	3rd Party
dynx_totalvalue	Google Analytics	Used to track product value in Google Ads		3rd Party
dynx_category	Google Analytics	Used for category tracking in Google Ads	-	3rd Party
ga4_analytics	Google Analytics	Serves to process behavior such as setting Google Analytics cookies, sending automatic and enhanced measurement events, and declaring common settings.		3rd Party
Google Conversion Tracking	Google Ads.	Used to transmit order information to Google Ads.	-	3rd Party
conversion ID	Google Ads.	An identification number used to transmit order information to Google Ads.	-	3rd Party
conversion labеl	Google Ads.	A label used to transmit information about successful orders to Google Ads.	-	3rd Party

How to Protect Your Car Key Fob from Relay Attacks

Why Relay Attacks Are So Effective

So, What Can You Do to Stay Safe?

Looking Ahead: Smarter Cars, Smarter Drivers

Related Posts

How to Program a Spare Car Key: Should You DIY or Call a Pro?

The Ultimate Guide to Opel, Peugeot, and Citroën Car Keys: Battery Replacement, Flip Key Issues, and Shell Compatibility

How Hot Weather Can Damage Your Car Key Fob – And What You Can Do About It

Can I order a replacement car key online with delivery?

Basic

Advertisement

Analytics

Additional software