6
3. Typical J1939 Wiring Topology
Most modern engine installations include a harness with built-in J1939
backbone, (check engine manufacturer’s documentation). If not, it is
critical to use twisted shielded pair with a drain wire (max length 40m)
terminated with 120 ohm resistors at each end. In addition, all stubs
should not exceed 1m in length, and a maximum of 30 nodes.
Engine and/or
Transmission
Backbone
(Max length 40m)
Termination
Resistor (120 ohm)
VeeCAN 128
Display
Stub (Max length 1m)
Termination
Resistor (120 ohm)
Node
(30 max)
