6. OBD Port Locks
- Anti-Theft Devices
What is it?
A physical “lockable” cover prevents thieves from plugging into the diagnostic port.
Pros:
- Cheap and easy to install.
Cons:
1. Thieves can still access the wiring behind the port.
Even if the port is physically blocked, a thief can:
- Remove interior panels
- Splice into the CAN wires behind the dash
- Connect directly to the network that controls key programming
This bypasses the port entirely.
They don’t need the port if they can reach the CAN lines.
2. The lock itself can be easily removed.
Most OBD port locks are:
- Plastic, thin metal or aluminium.
- Held in by small screws
- Accessible once the thief is inside the cabin
- A determined thief with basic tools (drill, pry bar, or grinder) can remove the lock in under a minute.
- Some can often be easily removed even without tools.
3. The OBD port is only one attack point
Thieves often bypass the OBD port completely by:
- Accessing headlight/CAN wiring behind the bumper
- Accessing CAN wires via wheel arch
- Getting to the BCM or ECU, not the OBD port
- Using alternative programming tools
Blocking the OBD port doesn’t stop these methods.
4. It doesn’t stop key cloning or relay theft
An OBD lock doesn’t protect you from:
- Relay amplifiers (steal the key’s signal)
- Key cloning
- Boosted proximity attacks
- Keyless start bypass tools
So the car can still be unlocked and started without touching the OBD port.
5. Not designed well for modern theft techniques
OBD locks were made for older-style thefts where:
- Thieves needed direct access to the port
- They couldn’t access CAN wiring easily
Modern thieves don’t rely on the port anymore.
They exploit:
- CAN injection
- BCM programming
- Wireless key cloning
- ECU replacement
A port lock doesn’t protect against any of this.
Conclusion:
An OBD Port lock is an ineffective way to prevent your vehicle from being stolen, due to the ease of removing them and lack of protection for other modern theft methods.