How to Protect a Keyless Car from Theft

Keyless cars were designed for convenience. Walk up, open the door, press a button, and drive away. No digging for keys. No turning ignition barrels.

Unfortunately, the same convenience has created new security gaps. Criminals are no longer smashing windows. They’re exploiting wireless signals, onboard networks, and electronic control systems. If you own a keyless vehicle, you need to understand how theft happens — and how to properly stop it.

At OJB Autocare, we deal with vehicle security daily. The pattern is clear: factory systems alone are not enough anymore.

How Keyless Car

Theft

Actually

Happens

Before you can prevent it, you need to understand it.

Relay Attacks

A relay attack is the most common form of keyless theft. It works by amplifying the radio frequency (RF) signal emitted by your key fob.

Two thieves typically work together:

• One stands near your house with a relay device.

• The other stands near your car.

The device captures and amplifies the key’s signal — even if it’s inside your home — and relays it to the vehicle. The car believes the key is present and unlocks. Engine start is authorised through the same wireless communication.

No forced entry. No broken glass. No visible damage.

Signal Cloning and Code

Grabbing

Some criminals intercept and replicate rolling codes used by remote key fobs. Although most modern vehicles use encrypted rolling codes, weaknesses still exist in older systems.

CAN Bus Attacks

This is more technical — and more concerning.

Modern vehicles operate through a Controller Area Network (CAN bus) system. It links modules such as the ECU, door control units, and ignition system.

Thieves access the CAN network through exposed wiring (sometimes behind headlights or wheel arches), inject commands directly into the system, and unlock or start the vehicle without the key.

This bypasses factory immobilisers entirely.

OBD Port Hacking

The OBD (On-Board Diagnostics) port can be exploited to program a new key if access is gained. Once inside the vehicle, criminals can reprogram the ECU and create a fresh key in minutes.

Why Factory

Immobilisers

Are No Longer

Enough

Most vehicles come with a factory immobiliser. It prevents the engine from starting without the correct digital handshake from the key.

That works — until the key signal is replicated or the CAN network is manipulated.

Factory systems were built for compliance, not determined criminal tactics. Insurance standards evolve slower than theft techniques.

If your security relies solely on the manufacturer’s immobiliser, you are depending on a system thieves already understand.

Practical Steps

to Protect a

Keyless Car

Security today requires layers. No single device is perfect. The goal is to reduce vulnerability at every stage.

Store Keys Away from Entry

Points

Keep keys away from front doors and windows. Signal relay devices can capture proximity signals even through walls.

Distance reduces signal strength.

Use a Faraday Pouch or

Faraday Box

A Faraday pouch blocks RF transmission from your key fob. When stored inside, the signal cannot be amplified.

However, this only protects against relay attacks. It does not stop CAN bus attacks or OBD programming.

Faraday protection is a basic layer — not a complete solution.

Disable Keyless Entry (If

Possible)

Some vehicles allow passive keyless entry to be disabled in the vehicle settings. This removes one attack surface entirely.

Many owners never check whether this option exists.

Install OBD Port Protection

OBD locks prevent unauthorised programming of new keys. They slow thieves down significantly.

Use a Visible Steering Lock

A quality steering wheel lock adds physical resistance and visual deterrence. Criminals prefer quick, silent jobs. Anything that increases time and attention works in your favour.

Improve Parking Security

• Park in a garage if possible

• Use driveway bollards

• Install CCTV

• Motion sensor lighting

Security outside the vehicle matters as much as security inside it.

Learn More: Insurance Approved S5 & S7 Trackers for New Cars in the UK

The Most

Effective

Upgrade:

CAN Bus

Immobiliser

If you want serious protection, you need a system that cannot be bypassed by signal amplification or CAN injection.

An advanced aftermarket immobiliser works differently from factory systems.

A modern CAN bus immobiliser integrates directly with the vehicle’s electronic architecture but adds a second layer of authentication. The vehicle will not start until a personalised PIN sequence is entered using existing vehicle buttons (steering wheel controls, door buttons, or centre console switches).

No radio frequency.
No key fob.
No visible device.

Even if criminals:

• Relay your key signal

• Clone your key

• Inject commands into the CAN network

The engine will not start without that PIN sequence.

This eliminates reliance on wireless authentication entirely.

Tracking

Systems vs

Immobilisers

A common mistake is assuming a GPS tracker is enough.

An S5 or S7 vehicle tracking system tells you where the vehicle went. It does not stop it being taken.

Recovery is not prevention.

A tracker is useful — especially for insurance compliance — but pairing it with an immobiliser creates both prevention and recovery coverage.

Thatcham and

TASSA

Standards

When choosing vehicle security, certification matters.

• Thatcham Research sets recognised UK automotive security standards.

• TASSA registered installers ensure correct installation and compliance.

Poor installation creates vulnerabilities. Exposed wiring, predictable module placement, or incorrect integration can defeat even strong hardware.

At OJB Autocare, installation is vehicle-specific. No copy-paste fits. Every integration is concealed and tested before handover.

Because the product is only as good as the install.

Insurance

Implications

Insurance providers are increasingly aware of keyless theft trends. Some high-risk vehicles now require approved security devices.

Adding a certified immobiliser or tracker can:

• Reduce premiums

• Prevent claim disputes

• Increase policy acceptance for high-risk models

Failing to upgrade security can cost more long term.

High-Risk

Vehicles

SUVs, luxury cars, and keyless vans are frequently targeted. Vans are particularly vulnerable due to tool theft and commercial value.

If your vehicle:

• Uses passive keyless entry

• Is parked on a driveway

• Is a high-demand model

You are statistically more exposed.

Ignoring that reality doesn’t reduce risk.

Layered Security

Is the Only

Real Strategy

Here’s the honest breakdown:

Faraday pouch alone? Not enough.
Factory immobiliser? Not enough.
Tracker alone? Not enough.

Effective protection combines:

• RF signal blocking

• Physical deterrents

• OBD protection

• CAN bus immobilisation

• Secure installation

Each layer closes a different vulnerability.

Final Thoughts

Keyless technology isn’t going away. Neither is electronic vehicle theft.

The difference between victims and protected vehicles usually comes down to whether the owner assumed factory security was sufficient.

It isn’t.

If you want proper protection, you need to understand how theft works — and install systems designed for how theft happens today, not ten years ago.

At OJB Autocare, vehicle security isn’t an afterthought. It’s a technical process built around prevention, integration, and concealment.

Because stopping theft is always better than tracking it afterward.