CAN-Bus stands for Controller Area Network bus. It’s vehicle bus standard that allow communication between Electronic Control Units in a vehicle.
The data travels down a pair of twisted wires which make up the network.
If you want more details then checkout Wikipedia
What advantages do CAN-Bus alarms have?
There are a large number of inputs that an alarm needs to be effective. These include the doors, boot and bonnet which can often be individual circuits. Then there is the central locking to wire up along with the inhibit inputs you’ll find on an conventional PLIP upgrade alarm.
It involves running a heap cables all over the vehicle, which takes time skill and experience to get right.
A less intrusive install with more functionality
With all the input data read by tapping into the CAN-Bus there is a lot less wiring to be done. There is also the potential for extra features which are simply not possible with a PLIP alarm.
How good the features on the alarm can vary massively between vehicles and what data is available to be read. Personally I love working on German vehicles as most include window open status which can be great as shown in the video.
Most vehicle manufactures don’t like CAN-Bus data being sent to the vehicle, Most alarms I deal with only read the CAN-bus data so there is no risk of creating error codes. All the Alarm output such as horn and hazard light controls are wired up directly to the relevant circuits.
Alarm Firmware
The other factor in how good a CAN-Bus alarm can be is the vehicle specific alarm firmware. I’m a big fan of Vodafone Automotive as the firmware is normally very well tested and works. They are also very good at doing updates.
I have been involved in sniffing CAN-Bus date on a number of vehicles so that alarm firmware can be programmed for new vehicles. It’s a time consuming process that to get things right and it’s important to test that everything is perfect before it gets flashed to an alarm and installed into a vehicle.
Junk CAN-Bus Alarms with poor firmware
Not all alarms are equal. There are a number of shit CAN-Bus alarm that get rebranded here in NZ so be warned.
As for the firmware, well if it’s not good then the alarm suffers the same pitfalls as a poorly installed PLIP alarm. I’ve seen numerous CAN-Bus alarm that don’t work well due to lazy data gathering and a lack of testing.
