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ALLDATA EDITORS NOTE

The Instrument Panel Gauges and Warning Indicators are not controlled by individual circuits. The ElectroMechanical Instrument Cluster (EMIC) assembly is driven by the BCM via the Programmable Communications Interface (PCI) data bus.

For diagnosis of the EMIC/MIC, Testing and Inspection

Fig.1 Instrument Cluster:

INSTRUMENT CLUSTER
The instrument cluster for this model is an ElectroMechanical Instrument Cluster (EMIC) that is located in the instrument panel above the steering column opening, directly in front of the driver. 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.

Fig.2 Instrument Cluster Components:

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 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 to the optional external RKE receiver through a connector receptacle that is integral to that unit. 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 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 stencil-like 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 sensors and switches 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.

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.

- 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 central locking feature of the power lock system. This feature will lock or unlock all doors based upon the input from the door cylinder lock switch. Door cylinder lock switches are used only 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, following 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 of standard head and park lamps, as well as optional front fog lamps. This includes support for headlamp beam selection and the optical horn feature, 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 data bus 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.

- 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 Air-bag 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.

- Interior Lighting 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.

- 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 (with the optional Vehicle Theft Security System only).

- 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 data bus 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 all other electronic modules on the PCI data bus with Vacuum Fluorescent Display (VFD) units 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 switch-(es), 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.

Fig.3 Gauges And Indicators - Gasoline Engine:

Fig.4 Gauges And Indicators - Diesel Engine:

The EMIC houses six analog gauges and has provisions for up to twenty-three indicators. The EMIC includes the following analog gauges:
- Coolant Temperature Gauge
- Fuel Gauge
- Oil Pressure Gauge
- Speedometer
- Tachometer
- Voltage Gauge

Some of the EMIC indicators are automatically configured when the EMIC is connected to the vehicle electrical system for compatibility with certain optional equipment or equipment required for regulatory purposes in certain markets. While each EMIC may have provisions for indicators to support every available option, the configurable indicators will not be functional in a vehicle that does not have the equipment that an indicator supports. The EMIC includes provisions for the following indicators:

- Airbag Indicator (with Airbag System only)
- Antilock Brake System (ABS) Indicator (with ABS or Rear Wheel Anti-Lock [RWAL] brakes only)
- Brake Indicator
- Cargo Lamp Indicator
- Check Gauges Indicator
- Cruise Indicator (with Speed Control only)
- Door Ajar Indicator
- Electronic Throttle Control (ETC) Indicator (with 2.7L Gasoline Engine only)
- Gear Selector Indicator (with Automatic Transmission only)
- High Beam Indicator
- Lamp Out Indicator
- Low Fuel Indicator
- Malfunction Indicator Lamp (MIL)
- Overdrive-Off Indicator (with Automatic Transmission only)
- Seatbelt Indicator
- Security Indicator (with Sentry Key Immobilizer & Vehicle Theft Security Systems only)
- Service Four-Wheel Drive Indicator (with Four-Wheel Drive only)
- Transmission Overtemp Indicator (with Automatic Transmission only)
- Turn Signal (Right and Left) Indicators
- Upshift Indicator (with Manual Transmission only)
- Washer Fluid Indicator
- Wait-To-Start Indicator (with Diesel Engine only)
- Water-In-Fuel Indicator (with Diesel Engine only)

Each indicator in the EMIC, except those located within one of the VFD units, is illuminated by a dedicated LED that is soldered onto the EMIC electronic circuit board. The LED units are not available for service replacement and, if damaged or faulty, the entire EMIC must be replaced. Cluster illumination is accomplished by dimmable incandescent back lighting, which illuminates the gauges for visibility when the exterior lighting is turned on. Each of the incandescent bulbs is secured by an integral bulb holder to the electronic 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. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.

The EMIC modules for this model are serviced only as complete units. The EMIC module cannot be adjusted or repaired. If a gauge, an LED indicator, a VFD unit, the electronic 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, hood and mask unit and the individual incandescent lamp bulbs with holders are available for individual service replacement.

The ElectroMechanical Instrument Cluster (EMIC) in 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 following information deals primarily with the instrument cluster functions of this unit. Additional details of the electronic body control functions of this unit may be found within the service information for the system or component that the EMIC controls. For example: Additional details of the audible warning functions of the EMIC are found within the Chime/Buzzer service information.

The EMIC is designed to allow the vehicle operator to monitor the conditions of many of the vehicle components and operating systems. The gauges and indicators 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 Programmable Communications Interface (PCI) data bus network. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/COMMUNICATION - OPERATION).

The EMIC microprocessor smooths the input data using algorithms to provide gauge readings that are accurate, stable and responsive to operating conditions. These algorithms are designed to provide gauge readings during normal operation that are consistent with customer expectations. However, when abnormal conditions exist such as high coolant temperature, the algorithm can drive the gauge pointer to an extreme position and the microprocessor can sound a chime through the on-board audible tone generator to provide distinct visual and audible indications of a problem to the vehicle operator. The instrument cluster circuitry may also produce audible warnings for other electronic modules in the vehicle based upon electronic tone request messages received over the PCI data bus. Each audible warning is intended to provide the vehicle operator with an audible alert to supplement a visual indication.

The EMIC circuitry operates on battery current received through a fused B(+) fuse in the Integrated Power Module (IPM) on a non-switched fused B(+) circuit, and on battery current received through a fused ignition switch output (RUN/START) fuse in the IPM on a fused ignition switch output (RUN/START) circuit. This arrangement allows the EMIC to provide some features regardless of the ignition switch position, while other features will operate only with the ignition switch in the On or Start positions. The EMIC circuitry is grounded through a ground circuit and take out of the instrument panel wire harness with an eyelet terminal connector that is secured by a ground screw to a ground location near the center of the instrument panel structural support.

The EMIC also has a self-diagnostic actuator test capability, which will test each of the PCI bus message-controlled functions of the cluster by lighting the appropriate indicators, positioning the gauge needies at several predetermined calibration points across the gauge faces, and illuminating all segments of the odometer/trip odometer and gear selector indicator Vacuum-Fluorescent Display (VFD) units. 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.