1998-2003 Dodge Durango electrical systems and electronics in detail
Central Timer Module
An electronic Central Timer Module (CTM) similar to those used on Dakota control a variety of electrical/electronic features. The CTM makes effective use of the multiplex wiring network to meet customer needs while reducing the number of wiring connections and simplifying the wiring system for reliability. The CTM provides the following functions:
- A pleasant chime warning for the following conditions: key-in-ignition when the driver's door is open, headlamps-on when driver's door is open, seat belt warning, check engine, air bag, antilock brakes (when installed), check gauges, low fuel and low washer fluid
- Two warning repetition rates: 50 chimes per minute for reminders and 180 chimes per minute for serious conditions requiring immediate attention:
— The serious-condition (high rate) tone sounds when the key is left in the ignition or the headlamps are left on
— The reminder (low rate) tone occurs when any of the other conditions are present
— Warnings of a serious conditions take precedence over reminders
- Variable warning chime duration
— Key-in-ignition and headlamp chime operate continuously as long as the door is open
- Ignition key lamp timer
- Intermittent wiper time delay
- Courtesy lamp time delay
- Battery protection system
— If the ignition is off and any door or the liftgate is left open, interior illumination will terminate after 15 minutes to avoid discharging the battery. If interior lamps are turned on with the dome lamp switch and the ignition is off, interior illumination will also terminate after 15 minutes
- Vehicle speed-sensitive intermittent windshield wiper delay
The CTM also supports the following available features which are described in the Safety and Security section:
- Power door lock system control including Enhanced Accident Response system, automatic locking and power lock inhibit
- Available remote keyless entry system with "Panic" alarm and illuminated entry feature
- Available vehicle theft alarm system
The CTM module is mounted to the right of the glove compartment, concealed by the instrument panel skin.
A factory-installed seven-circuit trailer wiring connector system provides direct connection to most trailer wiring without splicing is included in the Trailer Tow Preparation Package. A four-circuit adapter for the seven-circuit connector, also included with the package, ensures easy adaptation to the most common trailer wiring system. The chassis wiring harness includes a frame ground to facilitate installation of trailer tow wiring connectors that specify this type of ground.
The Durango wiring system shares reliability features with Dakota. It provides high reliability through advanced circuit design and improved connector systems. The fusing system for this vehicle has been enhanced, permitting the use of smaller gauge, lighter wires. Added circuits also mean that fewer systems are affected in the event of a malfunction and repair is easier because fewer components have to be tested to isolate the cause of the problem.
Connectors generally have low insertion forces and positive seating. Positive locking devices for terminals within the connectors and between mating halves ensure that connections are complete and secure.
Wiring from the engine compartment enters the passenger compartment through a sealed grommet in the dash panel to the left of the steering column. Engine compartment wiring connects to body wiring inside the passenger compartment for protection from the weather. Exterior wiring splices are sealed for reliability.
Instrument panel wiring is housed in a molded plastic trough that is attached to the back of the panel structure during assembly. This mounting protects the wiring and reduces the possibility of buzzes, squeaks and rattles (BSRs). Wire routing from the trough to individual components is clearly delineated to minimize handling of the harness during assembly, which can cause failures.
To reduce the potential for wiring damage in customer use, all passenger compartment wiring leading to sites beyond the instrument panel area - overhead console, rear speakers, dome lamps, rear air conditioning unit, taillamps, rear window defroster and CHMSL - is routed above the doors on the inboard surface of the body panels. And below the doors in troughs (under the scuff plate), wire troughs, harness retainer clips and grommets are used as needed to protect wiring from damage and minimize BSRs.
Wiring harnesses are mounted on the inboard surfaces of doors and other body panels rather than inside cavities to reduce the potential for damage from sharp edges and to make installation easier and more reliable. Door wiring is installed with the doors off the vehicle to enhance reliability.
For reliability, the wiring system provides separate ground circuits for each functional system wherever possible to prevent a single ground failure or circuit failure from affecting additional systems. All ground terminals are connected to threaded studs welded to the body structure in strategic locations that minimize ground-wire length.
New door ajar/courtesy lamp switches integral with the door and liftgate latches include a ground wire to ensure system reliability.
Power Distribution Center
A power distribution center (PDC), which slides onto the rear of the battery tray, is similar to that used on Dakota. It includes high-current cartridge fuses to protect major power distribution circuits and relays for all underhood power equipment. Proximity to the battery ensures highly effective protection for all underhood circuits against overload. Having relays in a single location simplifies vehicle assembly. Durango adds a fuse for each of the low beam HD/LPs. This helps to isolate any problems that might occur.
The junction block concept is shared with Dakota, but circuits are somewhat different due to additional features on Durango. The junction block combines the fuse block with electrical system terminal and distribution features. Wiring harnesses within the body - power train, headlamp and dash, instrument panel, body interior and the multiplex data network - plug into the junction block rather than to each other. Bus bars within the block distribute the electrical signals among the various circuits, reducing the need for splices and terminals, simplifying the wiring, and enhancing electrical system reliability. An additional mini fuse block has been added to provide more fusing. It is attached to the junction block.
Multiplex Data Network
Durango uses multiplex technology to meet customers' requirements for "intelligent" electronic features with reasonable cost and complexity. The multiplex wiring network provides high reliability by interconnecting electrical and electronic systems through a simple two-wire network, which winds throughout the vehicle. The onboard multiplex data network that delivers operating signals and data to a variety of electrical and electronic systems on Durango is similar to that used on Dakota. The following systems exchange information and control signals over the network:
- Instrument cluster gauges and most warning indicators
- Air bag control module
- JTEC Power Train Control Module
- Central Timing Module (CTM)
- Overhead console compass and mini-trip computer
- Four-wheel antilock brake control or rear-wheel antilock brake modules
- The instrument cluster receives signals over the network that operates the following functions:
- CHECK ENGINE warning indicator
- GENERATOR warning indicator
- CHECK GAUGES indicator
- Coolant temperature
- Fuel level sensor
- Battery voltage
- Oil pressure
- Brake system indicator
- ABS indicator
- CRUISE (Speed control) indicator
- Transmission temperature indicator
The rear-wheel antilock brake system sensor transmits its output signal over the data network to the JTEC PCM. This signal is electronically interpreted by the PCM as vehicle speed and forwarded to the instrument cluster, also over the data network, to drive the speedometer. Since the brake system sensor is standard on all models, this eliminates a separate speed sensor in the transmission. This feature is also used on other 1998 Dodge trucks.
To ensure that signals transmitted on the data network do not interfere with one another, only one unit at a time can transmit data on the network. Access to the network is gained through Chrysler-patented access circuitry incorporated in every unit connected to the network. Access is prioritized - high priority signals have immediate access, low priority signals must wait until the line is clear of higher priority transmissions. All electronic equipment on the network is also connected to the common data link connector for access to diagnostic information using a scan tool.
An electronic flasher operates both turn signals and hazard warning lamps as on Dakota. It simplifies the vehicle and enhances reliability by replacing two electro-mechanical flashers with a single, inherently more reliable, electronic device.