Part 1

INSTRUMENT CLUSTER
The DR Instrument Cluster is a new type of control module that includes the hardware and software necessary to function as the cluster and the Body Control Module. The Instrument Cluster houses the Speedometer, Tachometer, Fuel gauge, Coolant Temperature gauge, Oil Pressure gauge, and the Voltage gauge. The cluster positions all of the gauges using PCI bus messages received from the PCM. The cluster contains certain warning indicators, depending on engine type and options. Some of the indicators are hardwire inputs and some indicators are controlled via PCI bus messages. The warning chime tone generator is contained within the cluster. The cluster includes a Vacuum Fluorescent (VF) display for the PRNDL, Total and Trip Odometers. The VF will also display warning messages such as door ajar, low washer fluid level, engine hours, and no bus communications. The cluster has the ability to set and store DTC's, communicate on the PCI bus, display engine information, and display certain inputs using the DRB III.

The following systems are controlled either completely by the Instrument Cluster or in conjunction with other inputs received by hardwire or via the PCI bus:
- Audible Warnings
- Brake Lamp Control
- Brake Transmission Shift Interlock (BTSI)
- Cargo Lamp Control
- Central Locking
- Door Lock Inhibit
- Enhanced Accident Response
- Exterior Lighting Control
- Exterior Lighting Fail-Safe
- Heated Seat Control
- Interior Lamp Control
- Interior Lamps - Enhanced Accident Response
- Interior Lamps Load Shedding
- Lamp Out Indicator Control
- Panel Lamps Dimming Control
- Parade Mode
- Power Locks
- Remote Keyless Entry (RKE)
- Remote Radio Switch Interface
- Rolling Door Locks
- Turn Signal and Hazard Warning Lamp Control
- Vacuum Fluorescent Display Synchronization
- Vehicle Theft Security System (VTSS)

CAUTION: Instrument clusters used in this model automatically configure themselves for compatibility with the features and optional equipment in the vehicle in which they are initially installed.

The instrument cluster is programmed to do this by embedding the Vehicle Identification Number (VIN) and other information critical to proper cluster operation in electronic memory.

This embedded information is learned through electronic messages received from other electronic modules in the vehicle over the Programmable Communications Interface (PCI) data bus, and through certain hard wired inputs received when the cluster is connected to the vehicle electrically.

Once configured, the instrument cluster memory may be irreparably damaged and certain irreversible configuration errors may occur if the cluster is connected electrically to another vehicle; or, if an electronic module from another vehicle is connected that provides data to the instrument cluster (including odometer values) that conflicts with that which was previously learned and stored.

Therefore, the practice of exchanging (swapping) instrument clusters and other electronic modules in this vehicle with those removed from another vehicle must always be avoided. Failure to observe this caution may result in instrument cluster damage, which is not reimbursable under the terms of' the product warranty. Service replacement instrument clusters are provided with the correct VIN, and the certified odometer and engine hours values embedded in cluster memory, but will otherwise be automatically configured for compatibility with the features and optional equipment in the vehicle in which they are initially installed.

Fig. 1 Instrument Cluster:

Fig. 2 Instrument Cluster Components:

INSTRUMENT CLUSTER
The instrument cluster for this model is an Electro-Mechanical Instrument Cluster (EMIC) that is located in the instrument panel above the steering column opening, directly in front of the driver (Fig. 1). The remainder of the EMIC, including the mounts and the electrical connections, are concealed within the instrument panel behind the cluster bezel. Besides analog gauges and indicators, the EMIC module incorporates two blue-green digital Vacuum Fluorescent Display (VFD) units for displaying odometer/trip odometer information, engine hours, automatic transmission gear selector position (PRNDL), several warning or reminder indications and certain diagnostic information. The instrument cluster for this model also includes the hardware and software necessary to serve as the electronic body control module and is sometimes referred to as the Cab Compartment Node or CCN.

The EMIC gauges and indicators are visible through a dedicated opening in the cluster bezel on the instrument panel and are protected by a clear plastic cluster lens (Fig. 2) that is integral to a cluster lens, hood and mask unit. Just behind the cluster lens is the cluster hood and an integral cluster mask, which are constructed of molded black plastic. The cluster hood serves as a visor and shields the face of the cluster from ambient light and reflections to reduce glare, while the cluster mask serves to separate and define the individual gauges and indicators of the EMIC. A black plastic odometer/trip odometer switch button protrudes through dedicated holes in the cluster mask and the cluster lens, located near the lower edge of the cluster just to the left of the tachometer. The molded plastic EMIC lens, hood and mask unit has four integral mounting tabs, one each on the upper and lower outboard corners of the unit. These mounting tabs are used to secure the EMIC to the molded plastic instrument panel cluster carrier with four screws.

The rear of the cluster housing and the EMIC electronic circuitry are protected by a molded plastic rear cover, which is secured to the cluster housing with a single screw, while eight screws installed around the outside perimeter of the rear cover secure it to the cluster lens, hood and mask unit. The rear cover includes clearance holes for service access to each of the eleven incandescent bulb and bulb holder units installed on the cluster circuit board for general illumination lighting and for the cluster connector receptacles. The connector receptacles on the back of the cluster electronic circuit board connect the EMIC to the vehicle electrical system through three take outs with connectors from the instrument panel wire harness. The EMIC also has an integral interface connector on the back of the cluster circuit board that joins it through a connector receptacle that is integral to the optional external RKE receiver. The rear cover includes a molded receptacle and two latch features to secure the RKE receiver on vehicles that are so equipped.

Sandwiched between the rear cover and the lens, hood and mask unit is the cluster housing. The molded plastic cluster housing serves as the carrier for the cluster circuit board and circuitry, the cluster connector receptacles, the RKE interface connector, the gauges, a Light Emitting Diode (LED) for each cluster indicator, two Vacuum Fluorescent Display (VFD) units, an audible tone generator, the cluster overlay, the gauge pointers, the odometer/trip odometer switch and the switch button. The cluster overlay is a laminated plastic unit. The dark, visible, outer surface of the overlay is marked with all of the gauge dial faces and graduations, but this layer is also translucent. The darkness of this outer layer prevents the cluster from appearing 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 LED for each of the various indicators and the incandescent illumination lamps behind it to be visible through the outer layer of the overlay only through predetermined cutouts. A rectangular opening in the overlay at the base of both the speedometer and tachometer dial faces has a smoked clear lens through which the illuminated VFD units can be viewed.

Several versions of the EMIC module are offered on this model. These versions accommodate all of the variations of optional equipment and regulatory requirements for the various markets in which the vehicle will be offered. The microprocessor-based EMIC utilizes integrated circuitry and information carried on the Programmable Communications Interface (PCI) data bus network along with several hard wired analog and multiplexed inputs to monitor sensor and switch inputs throughout the vehicle. In response to those inputs, the internal circuitry and programming of the EMIC allow it to control and integrate many electronic functions and features of the vehicle through both hard wired outputs and the transmission of electronic message outputs to other electronic modules in the vehicle over the PCI data bus. (Refer to ELECTRONIC CONTROL MODULES/COMMUNICATION - DESCRIPTION - PCI BUS).

Besides typical instrument cluster gauge and indicator support, the electronic functions and features that the EMIC supports or controls include the following:
- Audible Warnings - The EMIC electronic circuit board is equipped with an audible tone generator and programming that allows it to provide various audible alerts to the vehicle operator, including chime tones and beep tones. An electromechanical relay is also soldered onto the circuit board to produce audible clicks that emulate the sound of a conventional turn signal or hazard warning flasher. (Refer to CHIME/BUZZER - DESCRIPTION).

- Brake Lamp Control - The EMIC provides electronic brake lamp request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for brake lamp control, excluding control of the Center High Mounted Stop Lamp (CHMSL), which remains controlled by a direct hard wired output of the brake lamp switch.

- Brake Transmission Shift Interlock Control - The EMIC monitors inputs from the brake lamp switch, ignition switch, and the Transmission Range Sensor (TRS), then controls a high-side driver output to operate the Brake Transmission Shift Interlock (BTSI) solenoid that locks and unlocks the automatic transmission gearshift selector lever on the steering column.

- Cargo Lamp Control - The EMIC provides direct control of cargo lamp operation with a load shedding (battery saver) feature which will automatically turn off the cargo lamp if it remains on after a timed interval.

- Central Locking - The EMIC provides support for the power lock system central locking feature. This feature will lock or unlock all doors based upon the input from the right or left door cylinder lock switch. Door cylinder lock switches are only available on models equipped with the optional Vehicle Theft Security System (VTSS).

- Door Lock Inhibit - The EMIC inhibits locking of the doors with the power lock switch when the key is in the ignition switch and the driver side front door is ajar. However, operation of the door locks is not inhibited under the same conditions when the Lock button of the optional RKE transmitter is depressed.

- Enhanced Accident Response - The EMIC monitors an input from the Airbag Control Module (ACM) and after an airbag deployment will immediately disable the power lock output, unlock all doors by activating the power unlock output, then enables the power lock output if the power lock switch input remains inactive for two seconds. This feature, like all other enhanced accident response features, is dependent upon a functional vehicle electrical system following the vehicle impact event.

- Exterior Lighting Control - The EMIC provides electronic head lamp and/or park lamp request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for the appropriate exterior lamp control for standard head and park lamps, as well as optional front fog lamps. This includes support for headlamp beam selection and optical horn, also known as flash-to-pass.

- Exterior Lighting Fail-Safe - In the absence of a headlamp switch input, the EMIC will turn on the cluster illumination lamps and provide electronic headlamp low beam and park lamp request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for default exterior lamp operation. The FCM will also provide default park lamp and headlamp low beam operation and the EMIC will turn on the cluster illumination lamps if there is a failure of the electronic communication between the EMIC and the FCM.

- Heated Seat Control - The EMIC monitors inputs from the ignition switch and electronic engine speed messages from the Powertrain Control Module (PCM) to control a high side driver output to the heated seat switch Light Emitting Diode (LED) indicators. This input allows the heated seat switches to wake up the heated seat module if the switch is actuated. The EMIC will de-energize the heated seat switch LED indicators which deactivates the heated seat system if the ignition switch is turned to any position except ON or Start, or if the engine speed message indicates zero. (Refer to HEATED SEATS - DESCRIPTION).

- Interior Lamp Control - The EMIC monitors inputs from the interior lighting switch, the door ajar switches, the cargo lamp switch, the reading lamp switches, and the Remote Keyless Entry (RKE) module to provide courtesy lamp control. This includes support for timed illuminated entry with theater-style fade-to-off and courtesy illumination defeat features.

- Interior Lamp Load Shedding - The EMIC provides a battery saver feature which will automatically turn off all interior lamps that remain on after a timed interval of about fifteen minutes.

- Interior Lamps - Enhanced Accident Response - The EMIC monitors inputs from the Airbag Control Module (ACM) and the Powertrain Control Module (PCM) to automatically turn on the interior lighting after an airbag deployment event ten seconds after the vehicle speed is zero. The interior lighting remains illuminated until the ignition switch is turned to the OFF position, at which time the interior lighting returns to normal operation and control. This feature, like all other enhanced accident response features, is dependent upon a functional vehicle electrical system following the vehicle impact event.

- Lamp Out Indicator Control - The EMIC monitors electronic lamp outage messages from the Front Control Module (FCM) located on the Integrated Power Module (IPM) in order to provide lamp out indicator control for the headlamps (low and high beams), turn signal lamps, and the brake lamps (excluding CHMSL).

- Panel Lamps Dimming Control - The EMIC provides a hard wired 12-volt Pulse-Width Modulated (PWM) output that synchronizes the dimming level of all panel lamps dimmer controlled lamps with that of the cluster illumination lamps.

- Parade Mode - The EMIC provides a parade mode (also known as funeral mode) that allows all Vacuum-Fluorescent Display (VFD) units in the vehicle to be illuminated at full (daytime) intensity while driving during daylight hours with the exterior lamps turned on.

- Power Locks - The EMIC monitors inputs from the power lock switches and the Remote Keyless Entry (RKE) receiver module (optional) to provide control of the power lock motors through high side driver outputs to the power lock motors. This includes support for rolling door locks (also known as automatic door locks), automatic door unlock, a door lock inhibit mode, and central locking (optional with Vehicle Theft Security System). (Refer to POWER LOCKS - DESCRIPTION).

- Remote Keyless Entry - The EMIC supports the optional Remote Keyless Entry (RKE) system features, including support for the RKE Lock, Unlock (with optional driver-door-only unlock, and unlock- all-doors), Panic, audible chirp, optical chirp, illuminated entry modes, an RKE programming mode, as well as optional Vehicle Theft Security System (VTSS) arming (when the proper VTSS arming conditions are met) and disarming.

- Remote Radio Switch Interface - The EMIC monitors inputs from the optional remote radio switches and then provides the appropriate electronic messages to the radio to select the radio operating mode, volume control, preset station scan and station seek features.

- Rolling Door Locks - The EMIC provides support for the power lock system rolling door locks feature (also known as automatic door locks). This feature will automatically lock all unlocked doors each time the vehicle speed reaches 24 km/h (15 mph) and, following an automatic lock event, will automatically unlock all doors once the ignition is turned to the OFF position and the driver side front door is opened.

- Turn Signal & Hazard Warning Lamp Control - The EMIC provides electronic turn and hazard lamp request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for turn and hazard lamp control. The EMIC also provides an audible click at one of two rates to emulate normal and bulb out turn or hazard flasher operation based upon electronic lamp outage messages from the FCM, and provides an audible turn signal on chime warning if a turn is signalled continuously for more than about 1.6 kilometers (one mile) and the vehicle speed remains greater than about 24 km/h (15 mph).

- Vacuum Fluorescent Display Synchronization - The EMIC transmits electronic panel lamp dimming level messages which allows modules with Vacuum Fluorescent Displays (VFD) to coordinate their illumination intensity with that of the EMIC VFD units.

- Vehicle Theft Security System - The EMIC monitors inputs from the door cylinder lock switches, the door ajar switches, the ignition switch, and the Remote Keyless Entry (RKE) receiver module, then provides electronic horn and lighting request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for the appropriate VTSS alarm output features.

- Wiper/Washer System Control - The EMIC provides electronic wiper and/or washer request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for the appropriate wiper and washer system features. (Refer to WIPERS/WASHERS - DESCRIPTION).