Central Timer Module: Operation: Notes

WARNING: This page is about a different car, the 2004 Dodge Dakota and 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

The Central Timer Module (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 Programmable Communications Interface (PCI) data bus network. The programming and all of the inputs allow the CTM to determine the tasks it needs to perform and their priorities, as well as both the standard and optional features that it should provide. The CTM then performs those tasks and provides those features through both PCI data bus communication with other modules and through hard wired outputs through a number of driver circuits, relays, and actuators. These outputs allow the CTM the ability to control numerous accessory systems.

The CTM operates on battery voltage received through two fuses in the Junction Block (JB) on two non-switched fused B(+) circuits, a fused ignition switch output (run-start) circuit, and a fused ignition switch output (run-acc) circuit. This arrangement allows the CTM to provide some features regardless of the ignition switch position. The CTM is grounded to the chassis. Two of these ground circuits are on the left inner cowl panel near the CTM, while the third is near the Airbag Control Module (ACM).

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