Daytona V6-181 2972cc 3.0L SOHC VIN 3 FI (1992)
Body Controller: Description and Operation
General Description
The body system consists of a combination of modules that communicate over the Chrysler Collision Detection multiplex system (CCD) bus. Through
the CCD bus, information about the operation of vehicle components and circuits is relayed to the appropriate module(s). Each module receives the same
information about a component or circuit as the other modules do. This significantly reduces the complexity of the wiring in the vehicle and the size of
the wiring harnesses.
The Chrysler Collision Detection multiplex system (CCD bus) consists of a twisted pair of wires. These wires run from one module to another. They
receive and deliver coded information between the modules. The information is coded to identify the message as well as the importance of the message.
When there are multiple messages trying to access the CCD bus at one time, the code determines which message has higher priority, which is then
allowed to access the bus first.
The two wires (D1) and (D2) of the twisted pair that make up the CCD multiplex system are called "bus+" (bus plus) and "bus-" (bus minus). Both wires
have a measurable voltage level of roughly 2.5 volts. In order to maintain the 2.5 volts on each line and provide a means of transportation for the coded
messages, there is a "Voltage divider network." This network consists of some modules with bias and some with termination. Bias is the part of the
voltage divider network that places. both bus+ and bus- at 2.5 volts. Termination in the is circuitry required to complete the voltage divider network and
also to provide some electromagnetic protection for the bus.
NOTE: Communication over the bus is essential to the proper operation of the vehicle's on-board diagnostic Systems and the DRBII. Problems with the
operation of the bus or DRBII must be corrected before proceeding with diagnostic testing. If there is a problem, refer to Information Bus for diagnostic
and repair procedures.
