CAN Bus
CAN bus is the network that lets the car's control units share data over a pair of wires.
What is CAN Bus?
Most cars have several networks at different speeds, linked by a gateway. U codes report communication faults on these networks. CAN uses two twisted wires, CAN High and CAN Low, and termination resistors at each end of the network. Faster variants such as CAN FD carry more data.
How it works
Each unit sends messages with priorities; all units on the bus can read them.
Why it matters for your car
Damaged wiring, water ingress or a faulty unit can disrupt the bus and cause several warning lights at once. A diagnostic tool can show which control units do not answer on the network, which helps find the location of a fault.
Other terms
- Acoustic Vehicle Alerting System (AVAS)
- Bike Rack (Bicycle Carrier)
- Bonnet Release (Hood Latch)
- Bump Stop
- Charge Point Operator (CPO)
- Connector Corrosion
- DC Fast Charging
- Driving Licence Categories
- Freeze Frame Data
- Heated Rear Window
- Idler Pulley
- Misfuelling (Wrong Fuel)
- Multimeter
- Oil Viscosity (Grade)
- Parking Lights (Sidelights)
- Six-Volt Electrical System
- Spot Welding (Resistance Spot Welding)
- State Of Charge (SoC)
- Torque Converter
- Vehicle Registration Document