Instrument Panel System

DESCRIPTION

Instrument Panel System
The instrument panel serves as the command center of the vehicle, which necessarily makes it a very complex unit. The instrument panel is designed to house the controls and monitors for standard and optional powertrains, climate control systems, audio systems, lighting systems, safety systems and many other comfort or convenience items. The instrument panel is also designed so that all of the various controls can be safely reached and the monitors can be easily viewed by the vehicle operator when driving, while still allowing relative ease of access to each of these items for service. See the owner's manual in the vehicle glove box for more information on the features, use and operation of all of the instrument panel components and systems.

Instrument Panel
Modular instrument panel construction allows all of the gauges and controls to be serviced from the front of the panel. In addition, most of the instrument panel electrical components can be accessed without complete instrument panel removal. If necessary, the instrument panel can be removed from the vehicle as an assembly.

Removal of the steering column opening cover and knee blocker provides access to the steering column mounts, the steering column wiring, the junction block, and much of the instrument panel wiring. Removal of the glove box provides access to the radio antenna coaxial cable, audio system power amplifier, intermittent wipe module, intermittent wipe relay, many of the heating and air conditioning system air distribution components, and additional instrument panel wiring.

Removal of the instrument cluster bezel allows access to the cluster assembly, the radio, the headlamp switch, the accessory switch plate, and the heating and air conditioning controls. Removal of the cluster assembly allows access to the cluster illumination and indicator lamp bulbs, and more of the instrument panel wiring. The instrument panel accessory switch plate has provisions for a cigar lighter, an accessory power outlet, the optional rear heater and air conditioner blower motor switch, and a passenger airbag on/off switch.

Removal of the instrument panel top cover allows access to the instrument panel speakers. Removal of the driver side instrument panel end cap provides access to the junction block fuses, circuit breakers, horn relay and electronic combination flasher. Removal of the engine cover provides access to the Central Timer Module (CTM), the power lock and Remote Keyless Entry (RKE) module, and the buzzer module.

Removal of the complete instrument panel is required for service of the heating and air conditioning system distribution ducts.

Instrument Cluster
A single instrument cluster is offered on this model. The cluster is an electromechanical unit that utilizes integrated circuitry and information carried on the Chrysler Collision Detection (CCD) data bus network for control of all gauges and many of the indicator lamps. This cluster also incorporates a digital Vacuum Fluorescent Display (VFD) for the odometer/trip odometer display functions. Some variations of this cluster exist due to optional equipment and regulatory requirements.

This instrument cluster includes the following analog gauges:

- Coolant temperature gauge
- Fuel gauge
- Oil pressure gauge
- Speedometer
- Voltmeter.

This instrument cluster also includes provisions for the following indicator lamps:

- Airbag indicator lamp
- Antilock Brake System (ABS) lamp
- Brake warning lamp
- Check gauges lamp
- Cruise-on indicator lamp (programmable)
- Headlamp high beam indicator lamp
- Low fuel warning lamp
- Low washer fluid warning lamp
- Malfunction indicator (Check Engine) lamp
- Overdrive-off indicator lamp (programmable)
- Seat belt reminder lamp
- Security lamp
- Transmission oil temperature warning lamp (programmable)
- Turn signal indicator lamps

This instrument cluster includes a provision for mounting the automatic transmission gear selector indicator in the lower right corner of the cluster.

The instrument cluster circuitry has a self-diagnostic actuator test capability, which will test each of the CCD bus message-controlled functions of the cluster by lighting the appropriate indicator lamps and positioning the gauge needles at several predetermined locations on the gauge faces in a prescribed sequence. For more information on this function, refer to Instrument Cluster in the Diagnosis and Testing.

On models equipped with a Central Timer Module (CTM), the instrument cluster circuitry also sends chime tone requests over a hard wired circuit to the CTM when it monitors certain conditions or inputs. The CTM replaces the buzzer module on models equipped with the optional Vehicle Theft Security System (VTSS).

The instrument cluster for this model is serviced only as a complete unit. If a cluster gauge or the cluster circuit board are faulty, the entire cluster must be replaced. The cluster lens and hood, the rear cluster housing cover, and the incandescent lamp bulbs and holders are available for service replacement.

OPERATION

Gauge
With the ignition switch in the On or Start positions, voltage is supplied to all gauges through the instrument cluster electronic circuit board. With the ignition switch in the Off position, voltage is not supplied to the gauges. The gauges do not accurately indicate any vehicle condition unless the ignition switch is in the On or Start positions.

All of the instrument cluster gauges, except the odometer, are air core magnetic units. Two fixed electromagnetic coils are located within the gauge. These coils are wrapped at right angles to each other around a movable permanent magnet. The movable magnet is suspended within the coils on one end of a shaft. The gauge needle is attached to the other end of the shaft.

One of the coils has a fixed current flowing through it to maintain a constant magnetic field strength. Current flow through the second coil changes, which causes changes in its magnetic field strength. The current flowing through the second coil is changed by the instrument cluster electronic circuitry in response to messages received on the Chrysler Collision Detection (CCD) data bus network.

The gauge needle moves as the movable permanent magnet aligns itself to the changing magnetic fields created around it by the electromagnets. The instrument cluster circuitry is programmed to move all of the gauge needles back to the low end of their respective scales after the ignition switch is turned to the Off position.

Indicator Lamp
Indicator lamps are located in the instrument cluster and are served by the cluster circuit board and connectors. Many of the indicator lamps in the instrument cluster are controlled by the instrument cluster circuitry in response to messages received over the Chrysler Collision Detection (CCD) data bus network.

The headlamp high beam indicator lamp, low washer fluid warning lamp, security lamp and turn signal indicator lamps are hard wired. The seat belt reminder lamp is controlled by the instrument cluster programming and by CCD data bus messages from the Airbag Control Module (ACM). The brake warning lamp is controlled by a hard wired input from the park brake switch and by CCD data bus messages from the Controller Anti-lock Brake (CAB). The instrument cluster circuitry uses CCD data bus messages from the Powertrain Control Module (PCM), ACM, and CAB to control all of the remaining indicator lamps.

In addition, certain indicator lamps in this instrument cluster are programmable. This feature allows those indicator lamps to be activated or deactivated with a DRB scan tool through the instrument cluster electronic circuitry for compatibility with certain optional equipment. The programmable indicator lamps for this model include the cruise-on indicator lamp, the overdrive-off indicator lamp and the transmission oil temperature warning lamp.

Each of the red indicator lamps in the instrument cluster is illuminated by a dedicated Light-Emitting Diode (LED). If an LED should fail, the entire instrument cluster must be replaced. The remaining indicator lamps in the instrument cluster use incandescent bulbs and holders. Each incandescent indicator lamp has a replaceable bulb and bulb holder.