Part 1 of 8

Fig.1 Insrument Cluster:

INSTRUMENT CLUSTER
The instrument cluster for this model is an ElectroMechanical Instrument Cluster (EMIC) module that is located in the instrument panel above the steering column opening, directly in front of the driver (Fig. 1). The EMIC gauges and indicators are protected by an integral clear plastic cluster lens, and are visible through a dedicated opening in the cluster bezel on the instrument panel. Just behind the cluster lens is the cluster hood and mask. The cluster hood serves as a visor and shields the face of the cluster from ambient light and reflections to reduce glare. The cluster overlay is a multi-layered unit. The dark, visible surface of the outer layer of the overlay is marked with all of the gauge identification and graduations, but this layer is also translucent. The darkness of this outer layer prevents the cluster from appearing too cluttered or busy by concealing the cluster indicators that are not illuminated, while the translucence of this layer allows those indicators and icons that are illuminated to be readily visible. The underlying layer of the overlay is opaque and allows light from the various indicator and illumination lamps behind it to be visible through the outer layer of the mask only through predetermined cutouts. On the lower edge of the cluster lens just right of center, a small molded rubber odometer/trip odometer switch knob boot covers the switch knob and seals the hole in the lens through which the knob protrudes. The remainder of the EMIC, including the mounts and the electrical connections, are concealed behind the cluster bezel. The molded plastic EMIC housing has four integral mounting tabs, two on the lower edge of the housing and one on each side. The EMIC is secured to the molded plastic instrument panel cluster carrier with four screws. All electrical connections to the EMIC are made at the back of the cluster housing through two take outs of the instrument panel wire harness, each equipped with a self-docking connector.

Two basic EMIC modules are offered: low-line, or high-line. Both of these modules utilize 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. (Refer to ELECTRONIC CONTROL MODULES/COMMUNICATION - DESCRIPTION). The EMIC also uses several hard wired inputs in order to perform its many functions. In addition to instrumentation and indicator lamps, the EMIC has hardware and/or software to support the following functions:

- Chime Warning Service - The EMIC performs the functions necessary to eliminate the need for a separate chime module. (Refer to CHIME/BUZZER - DESCRIPTION).

- Rear Window Defogger and Heated Mirror Control and Timer Service - The EMIC performs the functions necessary to eliminate the need for a separate control and timer module for the rear window defogger and heated mirror systems. (Refer to WINDOW DEFOGGER - DESCRIPTION) or (Refer to HEATED MIRRORS - DESCRIPTION).

- Vacuum Fluorescent Display (VFD) Dimming Service - The EMIC performs the functions necessary to eliminate the need for a separate VFD dimming module.

Both EMIC modules incorporate a blue-green electronic digital VFD for displaying odometer and trip odometer information. Some variations of each EMIC are necessary to support optional equipment and regulatory requirements. The low-line EMIC includes the following analog gauges:
- Fuel Gauge
- Speedometer

The low-line EMIC also includes provisions for the following indicator lamps:
- Airbag Indicator
- Antilock Brake System (ABS) Indicator
- Brake Indicator
- Coolant Temperature Warning Lamp
- Cruise Indicator
- Part Time and/or Full Time (Four-Wheel Drive) Indicators
- High Beam Indicator
- Liftgate Ajar Indicator
- Low Oil Pressure Warning Lamp
- Washer Fluid Indicator
- Malfunction Indicator Lamp (MIL)
- Seatbelt Indicator
- Sentry Key Immobilizer System (SKIS) Indicator
- Turn Signal (Right and Left) Indicators
- Upshift Indicator (Manual Transmission)
- Voltage Warning Lamp

The high-line EMIC. uses analog gauges in place of some of the indicator lamps found in the low-line EMIC. The highline EMIC includes the following analog gauges:
- Coolant Temperature Gauge
- Fuel Gauge
- Oil Pressure Gauge
- Speedometer
- Tachometer
- Voltage Gauge

The high-line EMIC cluster also includes the following additional indicator lamps, which are not found in. the low4ine EMIC:
- Check Gauges Indicator
- Low Fuel Indicator

Both EMIC modules include the following major components:
- Cluster Hood and Mask
- Cluster Housing (includes Circuit Board, Gauges, VFD, Odometer/Trip Odometer Switch, Odometer/Trip Odometer Switch Knob, and the Cluster Overlay)
- Cluster Housing Rear Cover
- Cluster Lens
- Odometer/Trip Odometer Switch Knob Boot

Cluster illumination is accomplished by adjustable incandescent back lighting, which illuminates the gauges for visibility when the exterior lighting is turned ON. Each of the EMIC indicator lamps is also illuminated by a dedicated incandescent bulb. Each of the incandescent bulbs is secured by an integral bulb holder to the circuit board from the back of the cluster housing.

Hard wired circuitry connects the EMIC to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the EMIC through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators.

The EMIC modules for this model are serviced only as complete units. The EMIC module cannot be adjusted or repaired. If an individual gauge, the circuit board, the circuit board hardware, the cluster overlay, or the EMIC housing are damaged or faulty, the entire EMIC module must be replaced. The cluster lens, the cluster hood and mask, the rear cluster housing cover, the odometer/trip odometer switch knob boot and the incandescent lamp bulbs with holders are available for individual service replacement.

The ElectroMechanical Instrument Cluster (EMIC) is designed to allow the vehicle operator to monitor the conditions of many of the vehicle components and operating systems. The gauges and indicator lamps in the EMIC provide valuable information about the various standard and optional powertrains, fuel and emissions systems, cooling systems, lighting systems, safety systems and many other convenience items. The EMIC is installed in the instrument panel so that all of these monitors can be easily viewed by the vehicle operator when driving, while still allowing relative ease of access for service. The microprocessor-based EMIC hardware and software uses various inputs to control the gauges and indicators visible on the face of the cluster. Some of these inputs are hard wired, but most are in the form of electronic messages that are transmitted by other electronic modules over the Chrysler Collision Detection (CCD) data bus network. (Refer to ELECTRONIC CONTROL MODULES/COMMUNICATION - OPERATION).

The EMIC also 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. (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). See the owner's manual in the vehicle glove box for more information on the features, use and operation of the EMIC.

Gauges
All gauges receive battery current through the EMIC circuitry when the ignition switch is in the ON or Start positions. With the ignition switch in the OFF position battery current is not supplied to any gauges, and the EMIC circuitry is programmed to move all of the gauge needles back to the low end of their respective scales. Therefore, the gauges do not accurately indicate any vehicle condition unless the ignition switch is in the ON or Start positions. All of the EMIC gauges, except the odometer, are air core magnetic units. Two fixed electromagnetic coils are located within each 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 pivot shaft, while 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 EMIC circuitry in response to messages received over the CCD data bus. The gauge needle moves as the movable permanent magnet aligns itself to the changing magnetic fields created around it by the electromagnets.

The gauges are diagnosed using the EMIC self-diagnostic actuator test. (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). Proper testing of the CCD data bus and the data bus message inputs to the EMIC that control each gauge require the use of a DRB III scan tool. Refer to the appropriate diagnostic information. Specific operation details for each gauge may be found elsewhere in this service information.

Vacuum-fluorescent Display
The Vacuum-Fluorescent Display (VFD) module is soldered to the EMIC circuit board. The display is active with the ignition switch in the ON or Start positions, and inactive when the ignition switch is in any other position. The VFD has several display capabilities, including odometer, trip odometer, software version display, and can display various diagnostic information. An odometer/trip odometer switch on the EMIC circuit board is used to control several of the display modes. This switch is actuated manually by depressing the odometer/trip odometer switch knob that extends through the lower edge of the cluster lens, just right of center. Actuating this switch momentarily with the ignition switch in the ON position will toggle the VFD between the odometer and trip odometer modes. Depressing the switch button for about two seconds while the VFD is in the trip odometer mode will reset the trip odometer value to zero. Holding this switch depressed while turning the ignition switch from the OFF position to the ON position will activate the EMIC self-diagnostic actuator test. Holding this switch depressed while turning the ignition switch from the ON position to the OFF position will display the EMIC software version for about two seconds. The VFD will automatically. display the message "no bus" in place of the odometer or trip odometer information if there is a loss of CCD data bus communication. The VFD will also display various information used in several diagnostic procedures. Refer to the appropriate diagnostic information for additional details on these VFD functions.

The VFD is diagnosed using the EMIC self-diagnostic actuator test. (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). Proper testing of the CCD data bus and the data bus message inputs to the EMIC that control some of the VFD functions requires the use of a DRB III scan tool. Refer to the appropriate diagnostic information. Specific operation details for the odometer and trip odometer functions of the VFD may be found elsewhere in this service information.

Indicator Lamps
Indicator lamps are located in various positions within the EMIC and are all connected to the EMIC circuit board. The anti-lock brake system lamp, brake warning lamp, four-wheel drive indicator lamps, headlamp high beam indicator lamp, low washer fluid warning lamp and turn signal indicator lamps are hard wired. The seat belt reminder lamp is controlled by the EMIC programming. The Malfunction Indicator Lamp (MIL) is normally controlled by CCD data bus messages from the Powertrain Control Module (PCM); however, if the EMIC loses CCD data bus communications, the EMIC circuitry will automatically turn the MIL ON and display the message "no bus" in the odometer VFD until CCD data bus communication is restored. The EMIC uses CCD data bus messages from the Powertrain Control Module (PCM), Airbag Control Module (ACM), and the Sentry Key Immobilizer Module (SKIM) to control all of the remaining indicator lamps. Different indicator lamps are controlled by different strategies; some receive fused ignition switch output from the EMIC circuitry cluster and have a switched ground, while others are grounded through the EMIC circuitry and have a switched battery feed.

The hard wired indicator lamps are diagnosed using conventional diagnostic methods. The EMIC and CCD bus message controlled indicator lamps are diagnosed using the EMIC self-diagnostic actuator test. (Refer to INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING). Proper testing of the CCD data bus and the data bus message inputs to the EMIC that control each indicator lamp require the use of a DRB III scan tool. Refer to the appropriate diagnostic information. Specific operation details for each indicator lamp may be found elsewhere in this service information.

Cluster Illumination
The EMIC has several illumination lamps that illuminated when the exterior lighting is turned ON with the headlamp switch. The illumination bright- ness of these lamps is adjusted by the panel lamps dimmer rheostat when the headlamp switch knob is rotated (clockwise to dim, counterclockwise to brighten). The illumination lamps receive battery current through the panel lamps dimmer rheostat and a fuse in the JB on a fused panel lamps dimmer switch signal circuit. The illumination lamps are grounded at all times. In addition, an analog/digital(A/D) converter in the EMIC converts the analog panel lamps dimmer rheostat input from the headlamp switch to a digital dimming level signal for controlling the lighting level of the VFD. The EMIC also broadcasts this digital dimming information as a message over the CCD data bus for use by the Compass Mini-Trip Computer (CMTC) in synchronizing the lighting level of its VFD with that of the EMIC.

The hard wired cluster illumination lamps are diagnosed using conventional diagnostic methods. Proper testing of the VFD dimming level and CCD data bus dimming level message function require the use of a DRB III scan tool. Refer to the appropriate diagnostic information.

Chime Service
The EMIC provides chime service for all available features in the chime warning system. The EMIC relies upon hard wired inputs from the driver side front door ajar switch, the headlamp switch, and the ignition switch wired in a series-parallel arrangement received through the key-in ignition switch sense circuit to provide chime service for the head/park lights-on reminder and the key-in ignition reminder. When the key-in ignition switch sense circuit is grounded with the ignition switch in the OFF position, the chime will sound repeatedly until the input becomes open or the ignition switch is turned to the ON position. For seat belt reminder chime service, the EMIC uses a hard wired input from the driver seat belt switch on the seat belt switch sense circuit. If the seat belt switch sense circuit is grounded (driver seat belt is not buckled) when the ignition switch is turned to the ON position, the chime will sound repeatedly until about six seconds have elapsed, until the input becomes open, or until the ignition switch is turned to the OFF position, whichever occurs first. The chime will not sound if the seat belt switch sense circuit is open (driver seat belt is buckled) at the moment the ignition switch is turned to the ON position, or if the circuit is open but changes to ground (driver seat belt is unbuckled) before six seconds after ignition-ON have elapsed.

The EMIC relies upon electronic message inputs received from other electronic modules over the CCD data bus to provide chime service for all of the remaining chime warning system features. Upon receiving the proper inputs, the EMIC activates the integral chime tone generator to provide the audible chime tone to the vehicle operator. The chime tone generator in the EMIC is capable of producing single chime tones or repeated chime tones at a rate of about fifty chime tones per minute. The internal programming of the EMIC determines the priority of each chime tone request input that is received, as well as the rate and duration of each chime tone that is to be generated. The hard wired chime inputs to the EMIC are diagnosed using conventional diagnostic methods. Proper testing of the CCD data bus and the data bus chime request message inputs to the EMIC require the use of a DRB III scan tool. Refer to the appropriate diagnostic information.

Rear Window Defogger/heated Mirror Control
The EMIC contains an integral timer and logic circuit to perform the rear window defogger/heated mirror control functions for the optional rear window defogger and heated mirror systems. The EMIC uses a hard wired input from the rear window defogger switch on the rear window defogger switch sense circuit and its control logic to determine the correct output to the rear window defogger relay. The EMIC controls the ground path of the rear window defogger relay control coil through an output on the rear window defogger relay control circuit. The EMIC is programmed to interpret each momentary ground signal it receives on the rear window defogger switch sense circuit as a request to change the current state of the output on the rear window defogger relay control circuit. Therefore, with the ignition switch in the ON position, the first ground input on the rear window defogger switch sense circuit turns the system ON, the second ground input turns the system OFF, and so forth. Once the rear window defogger system has been turned ON, it can be turned OFF manually by depressing the rear window defogger switch a second time or by turning the ignition switch to the OFF position. The timer function of the EMIC will also automatically turn the rear window defogger system OFF. The timer turns the system OFF after about ten minutes of operation; however, after the first timed interval has expired, each time the system is turned ON again during that same ignition cycle, the timer will automatically turn it OFF after about five minutes of operation.

The hard wired input and output of the EMIC rear window defogger/heated mirror control can be diagnosed using conventional diagnostic methods; however, there are no other diagnostic tools available for the EMIC rear window defogger/heated mirror control timer and logic circuitry. If the input and output components and circuits of the rear window defogger and heated mirror systems test OK, but the system fails to operate, the EMIC must be replaced.