Description and 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 illuminated entry module into a single unit. The base ctm also uses inputs from the door ajar switches, the headlamp switch and the key-in ignition switch to control the output to the dome lamp circuits, which allows the base ctm to provide load shedding to help protect the battery from becoming discharged.

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 highline 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.

One of the functions and features that both versions of the ctm support is the chime warning system.

The ctm contains a chime tone generator to perform the functions of the chime warning module.

The ctm uses hard-wired switch inputs, internal Programming, and a hard-wired chime request input from the instrument cluster circuitry to detect when a chime tone is required.

Both versions of the ctm are mounted under the passenger side end of the instrument panel, outboard of the instrument panel glove box opening. Refer to central timer module in the removal and installation section of group 8e - instrument panel systems for the service procedures.

This group covers the diagnosis and service of only the hard-wired inputs used by the ctm to determine that a chime tone should be generated. See central timer module in the diagnosis and testing section of this group for diagnosis of the base version of the ctm. For diagnosis of the high-line version of the ctm or of the ccd data bus, a drbiiit scan tool and the proper diagnostic procedures manual are recommended. The ctm cannot be repaired and, if faulty or damaged, it must be replaced.

Instrument cluster

The instrument cluster is an electromechanical unit that contains integrated circuitry and internal programming to perform a variety of functions. The instrument cluster circuitry monitors hard-wired switch inputs, as well as message inputs received from other vehicle electronic modules on the chrysler collision detection (ccd) data bus network.

The instrument cluster uses these many inputs along with its internal programming to provide hardwired chime tone requests to the central timer module (ctm), which performs the functions of the chime warning module on this model. The instrument cluster circuitry also has a self-diagnostic capability.

Refer to instrument cluster in the diagnosis and testing section of group 8e - instrument panel systems for more information on this feature.

The only instrument cluster diagnosis found in this group consists of confirming the viability of the hardwired chime request circuit between the instrument cluster circuitry and the ctm, and diagnosis of the hard-wired seat belt switch input to the instrument cluster. For diagnosis of the ccd data bus and the data bus message inputs, a drb scan tool and the proper diagnostic procedures manual are recommended.

Refer to instrument cluster in the removal and installation section of group 8e - instrument panel systems for the instrument cluster service procedures.

Refer to the diagnosis and testing section of group 8e - instrument panel systems for more information on the remaining hard-wired instrument cluster inputs. The instrument cluster chime warning circuitry cannot be repaired and, if faulty or damaged, the instrument cluster assembly must be replaced.

Driver door ajar switch

The driver door ajar switch is integral to the driver side front door latch. The switch closes a path to ground for the central timer module (ctm) when the driver door is opened, and opens the ground path when the driver door is closed.

The driver door ajar switch cannot be repaired and, if faulty or damaged, the door latch unit must be replaced. Refer to group 23 - body for the door latch service procedures.

Key-in ignition switch

The key-in ignition switch is integral to the ignition switch, which is mounted on the right side of the steering column. It closes a path to ground for the central timer module (ctm) when the ignition key is inserted in the ignition lock cylinder and the driver door ajar switch is closed (driver door is open).

The key-in ignition switch opens the ground path when the key is removed from the ignition lock cylinder.

The ground path is also opened when the driver door ajar switch is open (driver door is closed).

The key-in ignition switch cannot be repaired and, if faulty or damaged, the entire ignition switch must be replaced. Refer to group 8d - ignition systems for the service procedures.

Headlamp switch

The headlamp switch is located in the instrument panel, outboard of the steering column. It closes a path to ground for the central timer module (ctm) when the park or head lamps are on and the driver door ajar switch is closed (driver door is open). The headlamp switch opens the ground path when the headlamp switch is turned off. The ground path is also opened when the driver door ajar switch is open (driver door is closed).

The headlamp switch cannot be repaired and, if faulty or damaged, it must be replaced. Refer to headlamp switch in the removal and installation section of group 8e - instrument panel systems for the service procedures.

Driver seat belt switch

The driver seat belt switch is integral to the driver seat belt retractor assembly. The driver seat belt switch is normally closed, providing a ground signal to the instrument cluster when the ignition switch is in the on or start positions.

The seat belt switch monitors the amount of seat belt webbing wound onto the seat belt retractor spool. When the seat belt tip-half webbing is pulled out of the retractor far enough to engage the seat belt buckle-half, the switch opens the seat belt switch sense circuit.

The driver seat belt switch cannot be repaired and, if faulty or damaged, the entire driver seat belt and retractor unit must be replaced. Refer to Group 23 - Body for the service procedures.