CAN-BUS Alarms

What is CAN-BUS & how do CAN-BUS Alarms work?

CAN-BUS (Controlled Area Network BUS) is a communication system found in most modern vehicles that allow various electrical components to share data.

There are a large number of ECU’s (Electronic Control Units) found within modern vehicles. These control things like the engine, air-bags, transmission and body electronics. I’ll not list them all as there can be as many as 70 ECU’s in some vehicles.

The ECU’s (or Nodes) within a vehicle are connected by a pair of twisted wires that join the CAN-BUS. The advantage of CAN-BUS over a traditional wiring system is a huge reduction in the amount of cable required. For the ever-growing volume of electronics found in new cars the cables require would be immense! The CAN-BUS network increases reliability as it minimises the risk of damage to bulky wiring looms. (Think how fat a door loom could be and how many times it is going to move in its lifetime)

Wikipedia has a good page that goes into more detail about CAN-Bus for anyone who is interested…

The advantage of a CAN-BUS alarm

There are some modern vehicles where a traditional upgrade alarm installation would not be possible. Whilst traditional upgrade alarms can still be installed into a large number of CAN-BUS vehicles it can often be a complicated and time-consuming process.

CAN-BUS alarms simplify the installation process. There are fewer wires required to connect. The Controlled Area Network provides information such as doors open detection, keyless entry commands and on some vehicles it can even let the alarm know if a window is not fully closed! The alarm can then warn the driver that the vehicle is not fully secured, and disable the ultrasonic sensors to prevent a false alarm.

Each alarm needs the relevant software to be loaded in advance of the install and features are varied depending on vehicle make and model.