Central Timer Module

CENTRAL TIMER MODULE
The Durango (DN) utilizes a Central Timer Module (CTM). The CTM performs most of the typical functions a Body Control Module would perform. The Central Timer Module is located behind the left side kick panel. It contains 26-way, 16-way and 12-way connectors.

Fig.1 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 CTM is located behind the trim on the left cowl panel below the instrument panel. The base models are not equipped with the optional power lock system, the Remote Keyless Entry (RKE) system, the Vehicle Theft Security System (VTSS), or the remote radio controls. The high- line version of the CTM are used on vehicles that are equipped with one or more of those options.

The CTM uses information carried on the Programmable Communications Interface (PCI) data bus network along with many hard wired inputs to monitor many sensor and switch inputs. In response to those inputs, the circuitry and programming of the CTM allow it to supply the vehicle occupants with audible and visual information, and to control and integrate many functions and features of the vehicle through both hard wired outputs and the transmission of message outputs to other modules in the vehicle over the PCI data bus.

The features that the CTM supports or controls include the following:
- Automatic Door Lock - The high-line CTM provides an automatic door lock feature (also known as rolling door locks). This is a programmable feature.
- Battery Protection - The CTM provides a battery saver feature that performs timed load shedding whenever courtesy, reading, visor vanity, center console, glove box, or any exterior lamps are left on with the ignition switch in the Off position.
- Central Locking - The high-line CTM on vehicles equipped with the optional Vehicle Theft Security System (VTSS) includes a central locking/unlocking feature.
- Chimes - All versions of the CTM provide chime service and beep request service through an integral chime tone generator.
- Door Lock Inhibit - The high-line CTM provides a power door lock inhibit feature.
- Enhanced Accident Response - The high-line CTM provides an optional enhanced accident response feature. This is a programmable feature.
- Exterior Light Features - The CTM provides control of park lamps, fog lamps, and headlamps. This includes support for optical horn (also known as flash-to-pass), headlamp time delay, daytime running lamps (DRL - Canada only), and battery saver features.
- Interior Light Features - The CTM provides control of courtesy lamps, dome lamps, and the liftgate lamp. This includes support for a timed illuminated entry with fade-to-off, interior lighting delay courtesy illumination defeat, and battery saver features.
- Intermittent Wipe Control - The CTM provides control of the intermittent wipe delay and wipe-after-wash features for the front wiper and washer system. The high-line CTM also provides these same features for the optional rear wiper and washer system.
- Panic Mode - The high-line CTM provides support for the optional RKE system panic mode including horn, headlamp, and park lamp flash features.
- Power Lock Control - The high-line CTM provides the optional power lock system features, including support for the automatic door lock and door lock inhibit modes.
- Programmable Features - The CTM provides support for certain programmable features.
- Remote Keyless Entry - The high-line CTM provides the optional Remote Keyless Entry (RKE) system features, including support for the RKE Lock (with optional horn and park lamps flash), Unlock (with park lamps flash, driver-door-only unlock, and unlock-all-doors), Panic, and illuminated entry modes, as well as the ability to be programmed to recognize up to four RKE transmitters. The RKE horn, driver-door-only unlock, and unlock-all-doors features are programmable.
- Remote Radio Switch Interface - The high- line CTM monitors and transmits the status of the optional remote radio switches on the steering wheel.
- Speed Sensitive Intermittent Wipe Control - The CTM provides a speed sensitive front intermittent wipe feature.
- Vehicle Theft Security System - The high-line CTM provides control of the optional Vehicle Theft Security System (VTSS) features, including support for the central locking/unlocking mode and control of the Security indicator in the instrument cluster.

The high-line Central Timer Module (CTM) can also control some features of the audio system when the vehicle is equipped with remote radio switches. A high-line CTM is used on high-line versions of this vehicle. The CTM combines the functions of a chime/ buzzer module, an intermittent wipe module, an illuminated entry module, a remote keyless entry module, and a vehicle theft security system module in a single unit.

The high-line CTM also controls and integrates many of the additional electronic functions and features included on models with this option. The remote radio switch option is one of the features that the CTM controls. The CTM is programmed to send switch status messages over the Programmable Communications Interface (PCI) data bus to control the volume, seek, and pre-set station advance functions of the RAZ radio receiver. The CTM monitors the status of the remote radio switches located on the steering wheel through a hard wired circuit. The CTM then sends the proper switch status messages to the radio receiver. The electronic circuitry within the radio receiver responds to the switch status messages it receives by adjusting the radio settings as requested.

In addition, radio receivers connected to the PCI data bus have several audio system functions that can be diagnosed using a DRB III scan tool. Refer to the proper Diagnostic Procedures for more information on DRB III testing of the audio systems.

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

Many of the features in the vehicle controlled or supported by the CTM are programmable using the DRBIII scan tool. However, if any of the CTM hardware components are damaged or faulty, the entire CTM unit must be replaced. The hard wired inputs or outputs of all CTM versions can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM or the PCI data bus, the use of a DRBIII scan tool is required. Refer to the appropriate diagnostic information.

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 internal programming and all of these 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 hard wired outputs through a number of driver circuits, relays, and actuators.These outputs allow the CTM the ability to control numerous accessory systems in the vehicle.

The hard wired inputs to and outputs from the Central Timer Module (CTM) may be diagnosed and tested using conventional diagnostic tools and methods. Refer to the appropriate wiring information.

However, conventional diagnostic methods may not prove conclusive in the diagnosis of the CTM. In order to obtain conclusive testing of the CTM, the Programmable Communications Interface (PCI) data bus network and all of the modules that provide inputs to or receive outputs from the CTM must also be checked. The most reliable, efficient, and accurate means to diagnose the CTM, the PCI data bus network, and the modules that provide inputs to, or receive outputs from, the CTM requires the use of a DRBIII scan tool. Refer to the appropriate diagnostic information.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, SEAT BELT TENSIONER, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

The CTM operates on battery current 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, while other features will operate only with the ignition switch in the Accessory, On, and/or Start positions. The CTM is grounded to the chassis through three separate ground circuits. Two of these circuits are on the left inner cowl panel near the CTM, while the third circuit is grounded through the left side of the floor panel transmission tunnel 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 a Diagnostic Trouble Code (DTC) in electronic memory for any failure it detects. These DTCs can be retrieved and diagnosed using a DRBIII� scan tool. Refer to the appropriate diagnostic information.

HARD WIRED INPUTS
The hard wired inputs to the CTM include the following:
- Courtesy lamp switch sense
- Cylinder lock switch sense - high line with VTSS only
- Driver door ajar switch sense
- Driver door switch mux - high line with power locks only
- Fog lamp switch sense
- Front washer pump/motor control
- Front wiper park switch sense
- Fused B(+) (two circuits)
- Fused ignition switch output (Run/Acc)
- Fused ignition switch output (Run/Start)
- Ground (three circuits)
- Headlamp switch off sense
- High beam switch output
- Interior lamp defeat
- Intermittent front wiper mode sense
- Intermittent front wiper switch signal
- Key-in ignition switch sense
- Liftgate ajar switch sense
- Low beam switch output
- Park brake switch sense
- Park lamp switch sense
- Passenger door ajar switch sense
- Passenger door switch mux - high line with power locks only
- PCI bus circuit
- Radio control mux - high-line with remote radio switches only
- 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:
- Courtesy lamp driver
- Door lock relay output - high-line with power locks only
- Door unlock relay output - high-line with power locks only
- Driver door unlock relay output - high-line with power locks only
- Fog lamp relay control - with fog lamps only
- Front washer pump/motor control
- Front wiper park switch sense
- Front wiper relay control
- Glove box lamp driver
- High beam indicator driver
- Horn relay control - high-line with power locks only
- Interior lamp driver
- Left high beam driver
- Left low beam driver
- Park lamp relay control
- Rear wiper park switch sense - high line with rear wiper and washer system only
- Rear wiper relay control - high line with rear wiper and washer system only
- Right high beam driver
- Right low beam driver
- VTSS indicator driver - high-line with VTSS only

MESSAGING
The CTM uses the following messages received from other electronic modules over the PCI data bus:
- Airbag Deploy (ACM)
- Beep request (CMTC)
- Charging System Failure (PCM)
- Chime request (EMIC)
- Engine RPM (PCM)
- OK to Arm VTSS (PCM)
- Rear Washer Status (Heater-A/C Control)
- Rear Wiper Status (Heater-A/C Control)
- Security indicator request (SKIM)
- System Voltage (PCM)
- Valid/Invalid Key (SKIM)
- Vehicle Distance (PCM)
- Vehicle Speed (PCM)

The CTM provides the following messages to other modules over the PCI data bus:
- Door Ajar Status (EMIC)
- Liftgate Ajar Status (EMIC)
- Park Brake Status (CAB, EMIC, TCM)
- Radio Mode (Radio)
- Radio Preset Scan (Radio)
- Radio Seek Down (Radio)
- Radio Seek Up (Radio)
- Radio Volume Down (Radio)
- Radio Volume Up (Radio)