What this node sets
A Nexus can run two kinds of CAN network: the Haltech CAN bus for Haltech dashes, keypads and expanders, and the Vehicle CAN for talking to a car's factory modules. Enable them first, then use the CAN wiring node to decide which physical port carries each one.
The three settings
- CAN port: choose the port each enabled network is connected to.
- Terminating resistor: enable it only if the ECU is at one end of the network, meaning the first or last device on the cable run. A CAN bus needs termination at both ends and nowhere else.
- +12V CAN power supply: if you enabled CAN power in the Connections node, pick which pin or pins supply it here.
Getting termination right
This is the setting that causes the most trouble. With too little termination the signals reflect and devices drop out at random. Too much loads the bus down and does the same. A quick check with the power off: measure resistance between CAN High and CAN Low. About 60 ohms means both ends are terminated correctly. About 120 ohms means one end is missing, and a much lower reading means there are too many.
Use proper Haltech CAN cables so the pair stays twisted and the connectors seal. If you'd rather cut the cord to your laptop, see Wi-Fi.
