Body Control System

DESCRIPTION AND FUNCTIONAL OPERATION
The body electrical systems ON the 2002 AB HIGH LINE consists of three modules that communicate over the CCD bus (Chrysler Collision Detection multiplex system). There are two additional modules, the Powertrain Control Module (PCM) and the Controller Anti-Lock Brake (CAB) that are not part of the body system, but do utilize the CCD bus for communication. The CAB also utilizes the bus for diagnostics. The PCM sends and receives messages ON the CCD bus, however diagnostics are performed through the Serial Communication Interface of SCI, the same as previous years. All of the information about the functioning of all the system is organized, controlled, and communicated by the CCD bus.

Through the CCD bus, information about the operation of vehicle components and circuits is relayed quickly to the appropriate module(s). All modules receive all the information transmitted ON the bus even though a module may not require all the information to perform it's function. It will only respond to messages "addressed" to it through a binary coding process. This method of data transmission significantly reduces the complexity of the wiring in the vehicle and the size of wiring harnesses.

Fig. 1 Central Timer Module:

BODY CONTROL/CENTRAL TIMER MODULE
A Central Timer Module (CTM) is used on this vehicle when it is equipped with the optional Vehicle Theft Security System (VTSS). The CTM is located under the instrument panel, secured to the left center instrument panel support.

In addition to serving as the security system module, the CTM combines the functions of a chime buzzer module, an intermittent wipe module, an illuminated entry module, and a Remote Keyless Entry (RKE) module into a single unit. The CTM utilizes integrated circuitry and information carried on the Chrysler Collision Detection (CCD) data bus network along with many hard wired circuits to monitor many sensor and switch inputs throughout the vehicle. In response to those inputs, the CTM will control and integrate many functions and features of the vehicle through both hard wired outputs and the transmission of messages to other modules in the vehicle over the CCD data bus.

The features that the CTM supports or controls include the following:
* Automatic Door Lock
* Central Locking
* Chimes
* Courtesy Lamps
* Door Lock Inhibit
* Enhanced Accident Response
* Illuminated Entry
* Intermittent Wipe Control
* Power Lock Control
* Programmable Features Remote Keyless Entry
* Speed Sensitive Intermittent Wipe Control
* Vehicle Theft Alarm

Hard wired circuitry connects the CTM to the electrical system of the vehicle. Refer to the appropriate wiring information.

The CTM for this model is serviced only as a unit. Many of the features in the vehicle controlled or supported by the CTM are programmable using the DRB III scan tool. In addition, the CTM software is Flash compatible, which means it can be reprogrammed using Flash reprogramming procedures. The hard wired inputs or outputs of the CTM can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM, the CCD data bus, or the electronic message inputs to or outputs from the CTM, the use of a DRB III scan tool is required. Refer to the appropriate diagnostic information.

The Central Timer Module (CTM) controls and integrates many of the features and functions of the vehicle. The CTM monitors many hard wired switch and sensor inputs as well as those resources it shares with other modules in the vehicle through its communication over the Chrysler Collision Detection (CCD) data bus network. The programming and all of these inputs allow the CTM to determine the tasks it needs to perform and their priorities. The CTM then performs those tasks and provides those features through both CCD data bus communication with other modules and through hard wired outputs to a number of circuits, relays, and actuators. These outputs allow the CTM the ability to control numerous accessory systems.

The CTM operates on battery current received through fuses on a non-switched fused B(+) circuit, a fused ignition switch output (run-start) circuit, and two fused ignition switch output (run-acc) circuits. This arrangement allows the CTM to provide some features regardless of the ignition switch position. The CTM is grounded to the chassis through the instrument panel left center support and the back of the cross body member of the instrument panel support.

The CTM monitors its own internal circuitry as well as many of its input and output circuits, and will store a Diagnostic Trouble Code (DTC) in electronic memory for any failure it detects. These DTCs can be retrieved and diagnosed using a DRB III scan tool. Refer to the appropriate diagnostic information.

Hard Wired Inputs
The hard wired inputs to the CTM include the following:
* Auxiliary door ajar switch sense
* CCD bus-
* CCD bus+
* Cylinder lock switch mux
* Driver door ajar switch sense
* Fused B(+)
* Fused ignition switch output (run-acc) - two circuits
* Fused ignition switch output (run-start)
* Ground - two circuits
* Key-in ignition switch sense
* Passenger door ajar switch sense
* Power door lock motor B(+) lock
* Power door lock motor B(+) unlock
* Washer switch sense
* Wiper park switch sense
* Wiper switch mode sense
* Wiper switch mode signal

Hard Wired Outputs
The hard wired outputs of the CTM include the following:
* CCD bus-
* CCD bus+
* Courtesy lamp switch output
* Door lock driver
* Door unlock driver
* Headlamp relay control
* Horn relay control
* VTSS indicator driver
* Wiper motor relay control

Messaging
The CTM uses the following messages received from other electronic modules over the CCD data bus:
* Airbag Deploy (ACM)
* Charging System Failure (PCM)
* Engine RPM (PCM)
* System Voltage (PCM)
* Vehicle Speed (PCM)
* Voltage Fault (PCM)

The CTM provides the following messages to other electronic modules over the CCD data bus:
* Engine Enable (PCM)