How it works

How thieves steal cars through the OBD port

There's no broken glass, no alarm, and often no sign anything happened until the driveway is empty. Modern vehicle theft is closer to a software exploit than a break-in.

Step 1 — Getting inside

The thief needs physical access to the cabin, but not violent access. Common methods include a relay attack (two devices relay your key fob's signal from inside your house to the car, unlocking it), exploiting an unlocked door, or in some cases jamming the lock signal as you walk away so the car never actually locks.

Australian Bureau of Statistics data shows the majority of car thefts happen at the owner's home — which is exactly where your keys sit near a front door, within relay range.

Step 2 — Finding the port

The OBD-II port is standardised. On almost every vehicle it's under the dash on the driver's side, within reach of the footwell. A thief doesn't need to search — they already know where it is on your make. Here's how to find yours.

Step 3 — Programming a key

This is the part people find surprising. The OBD port isn't just for reading fault codes. It's the same channel a locksmith uses to pair a replacement key when you lose one — a genuine, necessary function.

A key programmer plugs in, talks to the immobiliser, and enrols a blank transponder key. Depending on the vehicle it takes anywhere from 30 seconds to a few minutes. The car now has a second legitimate key that starts it.

No forced ignition, no hot-wiring. As far as the vehicle is concerned, an authorised key is being used.

Step 4 — Driving away

The alarm doesn't sound, because the car isn't being broken into. The immobiliser doesn't engage, because a valid key is present. Tracking devices help recovery but don't prevent the theft.

How common is this in Australia?

The numbers are significant and moving in the wrong direction:

• Victoria recorded 33,212 vehicles stolen in the year to September 2025 — up around 28% year on year, according to Crime Statistics Victoria.
• Victoria Police have seized more than 1,100 key-cloning devices since the start of 2025.
• Insurance figures put motor theft claims at roughly 29,000 nationally with about $485 million in losses.
• Queensland is the next highest state by volume after Victoria.

Not every one of those is an OBD attack — but electronic methods now account for a substantial share, and they're the fastest-growing category.

Why traditional security doesn't help

What actually blocks it

Since the attack depends on the OBD port carrying data, the countermeasures all target that port:

1. Physical port locks — a steel cover. Cheap, instant, but can be cut or pried. Compared here.
2. Port re-pinning — rewires the connector so a scanner reads nothing. You carry an adapter for legitimate diagnostics.
3. Aftermarket immobilisers — a hidden secondary cut-off. Effective, but usually needs professional installation.

Combine any of these with a Faraday pouch for your keys and you've addressed both the entry method and the theft method.

Free things worth doing tonight

• Keep keys away from the front door — relay attacks need proximity.
• Check the car actually locked; listen for the click, watch the mirrors fold.
• Park with wheels turned toward the kerb — it complicates towing.
• If you have a garage, use it. Sounds obvious; most stolen cars were in an open driveway.