Dakota 4WD V6-3.9L VIN X (1997)
Central Timer Module ( CTM ) High Option: Description and Operation
Central Timer Module
INTRODUCTION
Central Timer Module
The Central Timer Module (CTM) is used to supply the vehicles occupants with visual and audible information, control various vehicle functions,
and provide a centralized power distribution for the passenger compartment. To both provide and receive vehicle information the BCM is
interfaced to the CCD Bus.
Power for the CTM is supplied from three sources. Circuit F12 supplies power to the CTM in the START and RUN position. This circuit is
protected by a 10 Amp fuse located in the junction block.
Power is also supplied to the CTM on circuit F35. This circuit is HOT at all times and protected by a 20 Amp fuse located in the junction block.
In the RUN position circuit V6 provides battery power to the CTM. This circuit is protected by a 20 Amp fuse located in the junction block.
Ground for the ECM is provided by circuits Z1 and Z2.
CCD Bus interface is accomplished on circuits D1 and D2. The D1 circuit is used for Bus (+), and D2 is for Bus (-).
SYSTEM OPERATION
Central Timer Module
Two versions of the Central Timer Module (CTM) are available on this vehicle, a base version and a high-line version. The base version of the
CTM is used on base models of the vehicle. The base version of the CTM combines the functions of a chime/buzzer module, an intermittent wipe
module, and an ignition lamp time delay relay in a single unit.
The high-line version of the CTM is used on highline vehicles. The high-line CTM provides all of the functions of the base version CTM, but also
is used to control and integrate many of the additional electronic functions and features included on the high- line models. The high-line version of
the CTM contains a central processing unit and interfaces with other modules in the vehicle on the Chrysler Collision Detection (CCD) data bus
network.
The CCD data bus network allows the sharing of sensor information. This helps to reduce wire harness complexity, reduce internal controller
hardware, and reduce component sensor current loads. At the same time, this system provides increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
The power lock and Remote Keyless Entry (RKE) systems are two of the systems that the high-line CTM controls. The high-line CTM receives
hard-wired inputs from the power lock switches, CCD message inputs from the Powertrain Control Module (PCM) and Airbag Control Module
(ACM), and coded radio signal inputs from the RKE transmitters. In response to those inputs, the internal programming of the CTM sends the
proper outputs to control the power lock motors, the horn relay, and the courtesy lamps.
Some of the features and functions of the power lock and Remote Keyless Entry (RKE) systems made possible because of the communication of
the CTM on the CCD data bus network include:
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A door-lock inhibit feature which prevents the power lock system from being energized with a power door lock switch if the key is in the
ignition and/or the headlamps are on. However, the locks can still be operated manually with a key or energized with the RKE transmitter.
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An enhanced accident response feature will prevent the doors from locking, then unlock both doors after receiving a CCD message from the
ACM indicating a frontal impact requiring airbag deployment. This feature will also turn on the courtesy lamps ten seconds after receiving the
ACM deployment message, if the CCD vehicle speed message from the PCM indicates the vehicle is not moving. Of course, these responses
are dependent upon functional battery power and wiring circuitry following the impact.
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Rolling door locks is a programmable feature of the power lock system. This feature will automatically lock all of the doors after the vehicle
reaches a speed of about 24 kilometers-per-hour (15 miles-per-hour) or greater. This feature will also lock the doors if a door is opened,
then closed again at any speed above 24 kilometers-per-hour (15 miles-per-hour). This feature can be enabled or disabled using the DRB
scan tool and the proper Diagnostic Procedures.
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A programmable feature of the RKE system is the enabling or disabling of the horn chirp following the RKE Lock function. This feature can
be enabled or disabled using the DRB scan tool and the proper Diagnostic Procedures.
The horn relay is one of the outputs that the high-line CTM can control. The high-line CTM is programmed to energize or de-energize the horn
relay in response to certain inputs from the Vehicle Theft Security System (VTSS) and the Remote Keyless Entry (RKE) system.
One of the features that the high-line CTM supports and controls is the Vehicle Theft Security System (VTSS). In the VTSS, the CTM receives
hard-wired inputs from the door jamb, door lock cylinder, and ignition switches. The programming in the CTM allows it to process the
information from these inputs and send control outputs to energize or de-energize the headlamp relay, horn relay, and the Security lamp. The CTM
also sends CCD data bus messages to the Powertrain Control Module (PCM) to control the engine no-run feature of the VTSS
The CTM also contains the receiver and control logic for the power lock and Remote Keyless Entry (RKE) systems, which are integrated into the
arming, disarming, and triggering functions of the VTSS.
