Can Communication Signal Generation

WARNING: This page is about a different car, the 2015 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.

Termination circuits (resistors) are connected across the CAN communication system. When transmitting a CAN communication signal, each control unit passes a current to the CAN-H line and the current returns to the CAN-L line.

Fig 1: CAN Communication System Diagram (CAN-H Line And CAN-L Line)
Courtesy of NISSAN NORTH AMERICA, INC.
The current flows separately into the termination circuits connected across the CAN communication system and the termination circuits drop voltage to generate a potential difference between the CAN-H line and the CAN-L line.

Fig 2: CAN-H Line And CAN-L Line Voltage Graph
Courtesy of NISSAN NORTH AMERICA, INC.

NOTE:
A signal with no current passage is called "Recessive" and one with current passage is called "Dominant".
The system produces digital signals for signal communications, by using the potential difference.

Fig 3: CAN Signal Waveform
Courtesy of NISSAN NORTH AMERICA, INC.