CCD Bus
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1991 Plymouth Voyager, 1991 Plymouth Grand Voyager, 1991 Dodge Grand Caravan, 1991 Dodge Caravan, and 1991 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
The CCD bus is a twisted pair of wires traveling from module to module receiving and delivering coded information. The code identifies the message and its importance. When multiple messages attempt to access CCD bus at once, code assigns priority ranking. The 2 twisted wires used by the CCD bus system are called Bus "+" and Bus "-". Both wires carry approximately 2.5 volts.