Instrument Cluster - Description
DESCRIPTION
The instrument cluster (2) for this vehicle is located in the instrument panel directly in front of the driver and is only visible through the three openings in the instrument cluster bezel. The remainder of the instrument cluster, including the mounts and the electrical connections, are concealed within the instrument panel behind the cluster bezel (1). The instrument cluster for this vehicle includes the hardware and software necessary to serve as the electronic body control module and is also known as the Cab Compartment Node or (CCN).
Besides analog gauges and indicators, the CCN module incorporates one standard blue-green digital Vacuum Fluorescent Display (VFD) unit. A second optional VFD unit is available in some vehicles. The standard VFD is a fixed segment unit for displaying odometer information, automatic transmission gear selector position (PRNDL), and several other indicators. The optional compass/temperature VFD unit is a large fixed segment display. The optional Electronic Vehicle Information Center (EVIC) VFD unit is a large re-configurable display unit. These optional VFD units serve as the visual display for the compass, the outside temperature, the trip computer, the audio system settings as well as the user interface for the customer programmable features, numerous textual warning or reminder indicators and certain diagnostic information depending upon vehicle equipment.
The CCN gauges and indicators are visible through three dedicated openings in the cluster bezel and are protected by a clear plastic cluster lens (5). Nine integral latch formations on the lens secure it to the cluster hood and mask unit (4) as well as the cluster housing (2). Just behind the cluster lens is the cluster hood and integral mask, which is constructed of molded black plastic. The 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 trims the outside perimeter of the cluster overlay. The hood and mask unit has eight integral latch features that secure it to the outer perimeter of the cluster housing. The hood and mask unit also has two integral mounting tabs on the lower corners that combine with the tabs integral to the cluster housing to secure the bottom of the CCN to the molded plastic instrument panel cluster carrier with two screws.
The rear of the cluster housing and the CCN electronic circuitry are protected by a molded white plastic rear cover (1), which is also secured to the cluster housing by integral latch features. The rear cover includes clearance holes for the four cluster connector receptacles. The connector receptacles on the back of the cluster electronic circuit board connect the CCN to the vehicle electrical system through four take outs with connectors from the instrument panel wire harness.
Sandwiched between the rear cover and the lens and hood unit is the cluster housing. The molded white plastic cluster housing serves as the carrier for the cluster circuit board and circuitry, the cluster connector receptacles, the two major and two minor gauges, a Light Emitting Diode (LED) for each cluster indicator, the VFD display units, an audible tone transducer, several LED units for general cluster illumination, the cluster overlay, and the gauge pointers. The standard equipment molded black plastic odometer/trip odometer switch button (3) extends from the face of the cluster housing through dedicated holes in the cluster mask and the cluster lens adjacent to their respective VFD units. A black rubber grommet seals the switch button to the clearance hole in the lens. The cluster housing also has four integral mounting tabs, one on each upper and lower corner of the housing.
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 illumination lamps behind it to be visible through the outer layer of the overlay through predetermined stencil-like cutouts. Openings in the overlay at the base of the tachometer and the minor gauge set dial faces have smoked clear lenses through which the illuminated VFD units can be viewed.
Several versions of the CCN module are offered on this vehicle. These versions accommodate all of the variations of optional equipment and regulatory requirements for the various markets in which the vehicle is offered. The microprocessor-based CCN utilizes integrated circuitry and information carried on the Controller Area Network (CAN) data bus and the Local Interface Network (LIN) data bus 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 CCN 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 CAN and LIN data busses. Communication - Description.
VEHICLE SYSTEMS SUPPORT
Besides typical instrument cluster gauge and indicator support, the electronic functions and features that the CCN supports or controls include the following:
- Audible Warnings - The CCN electronic circuit board is equipped with an audible tone transducer and programming that allows it to provide various audible alerts to the vehicle operator. These alerts include single chime tones and continuous slow or fast tones. An electromechanical relay is also soldered onto the circuit board to produce audible clicks that are used to emulate the sound of a conventional turn signal or hazard warning flasher.
- Compass/Temperature Display Support - The CCN provides support for each of the functions and features of the compass/temperature display, as well as for the odometer push button switch, which also provides user inputs to control the compass/temperature display options.
- Electronic Vehicle Information Center Display Support - The CCN provides support for each of the functions and features of the Electronic Vehicle Information Center (EVIC) display. This includes support for the compass, thermometer and audio system mode, customer programmable features, textual warnings, premium Tire Pressure Monitor (TPM), trip computer, U-Connect(TM) Hands-Free communication and the switch inputs from the two EVIC rocker switches located on the front surface of the steering wheel spokes that are used to control and configure many of the displays. This also includes display arbitrator programming, which controls the priorities, sequences, and transition of information that is displayed in the EVIC display, particularly when multiple display requests are received simultaneously.
- Enhanced Accident Response Support - The CCN monitors inputs from the Occupant Restraint Controller (ORC) and the Powertrain Control Module (PCM) to automatically turn ON the interior lighting after an airbag deployment event, 10 seconds after the vehicle speed is zero. The interior lighting remains illuminated until the key is removed from the ignition switch lock cylinder, at which time the interior lighting returns to normal operation and control. These Enhanced Accident Response System (EARS) features are each dependent upon a functional vehicle electrical system following the vehicle impact event.
- Exterior Lighting Switch Support - The CCN monitors electronic exterior lighting switch, and turn signal switch status messages from the Steering Control Module (SCM) on the steering column over the LIN data bus and transmits the appropriate electronic exterior lighting and turn signal request messages to the Totally Integrated Power Module (TIPM) over the CAN data bus to support the exterior lighting functions.
- Horn Switch Support - On vehicles without the optional EVIC, the CCN receives a hard wired input from the horn switch on the steering wheel. On vehicles with the optional EVIC, the CCN receives electronic horn switch status messages from the Steering Wheel Switch Module (SWSM) over the LIN bus. In either case, the CCN then provides electronic horn request messages over the CAN data bus to support the horn function.
- Interior Lamp Load Shedding - The CCN provides a battery saver feature which will automatically turn OFF all interior lamps if they remain ON after a timed interval of about ten minutes.
- Interior Lighting Control - The CCN monitors electronic messages and hard wired inputs from the reading lamp switches, the Sentry Key REmote Entry Module (SKREEM) (also known as the Wireless Control Module/WCM), the Steering Control Module (SCM) and the Totally Integrated Power Module (TIPM) to provide courtesy lamp control. This includes support for timed illuminated entry with theater-style fade-to-OFF and courtesy illumination DEFEAT features.
- Local Interface Network Master Module - The CCN is the master module for the LIN data bus. In this role it gathers information from the compass sensor, the Heated Seat Module (HSM), the instrument panel switch pod, the Steering Wheel Switch Module (SWSM), the SCM and the remote compass module, then either acts on that information directly or places electronic messages on the CAN data bus for use by other modules
- Panel Lamps Dimming Control - The CCN monitors electronic dimming level messages received from the panel lamps dimmer switch input to the SCM over the LIN data bus, then provides both a hard wired 12-volt Pulse-Width Modulated (PWM) output and electronic message outputs over the CAN data bus and the LIN data bus that synchronizes the dimming level of all panel lamps dimmer controlled lamps with that of the cluster general illumination lighting.
- Wiper and Washer Switch Support - The CCN monitors electronic wiper switch and washer switch status messages from the SCM on the steering column over the LIN data bus and transmits the appropriate electronic wiper and washer request messages to the TIPM over the CAN data bus to support the wiper and washer system functions, including the headlamps-on with wipers programmable feature.
VACUUM-FLUORESCENT DISPLAYS
The CCN includes the following Vacuum Fluorescent Display (VFD) units:
- Odometer Display (15) - includes Cruise indicator (13), Four-Wheel Drive (4WD) indicator for domestic market vehicles, Gear Selector indicator (12), Malfunction Indicator Lamp (MIL) (16) for domestic market vehicles and Tire Pressure Monitor (TPM) indicator (14).
- Compass-Temperature or Electronic Vehicle Information Center Display (31)
The odometer and trip odometer are standard factory-installed equipment in all instrument clusters. The odometer and trip odometer are displayed in a common electronic, blue-green VFD unit. This VFD unit is soldered onto the cluster electronic circuit board, and is visible through a window with a smoked clear lens located on the lower edge of the tachometer in the lower right area of the cluster overlay. The dark lens over the VFD prevents the indicator from being clearly visible when it is not illuminated.
The odometer and trip odometer information are not displayed simultaneously. The trip odometer reset switch on the instrument cluster circuit board toggles the display between odometer and trip odometer modes by depressing the odometer/trip odometer switch button that extends through the lower edge of the cluster lens, just left of the minor gauge set. When the trip odometer information is displayed, the text TRIP A or TRIP B is also illuminated in the lower right corner of the odometer/trip odometer VFD in a blue-green color and at the same lighting level as the trip odometer information.
The odometer and trip odometer information are stored in the instrument cluster memory. This information can be increased when the proper inputs are provided to the instrument cluster, but the information cannot be decreased. The odometer can display values up to 999,999 kilometers (999,999 miles). The odometer latches at these values, and will not roll over to zero. The trip odometer can display values up to 999.9 kilometers (999.9 miles) before it rolls over to zero.
The odometer display does not show leading zeroes, does not have a decimal point and will not show values less than a full unit (kilometer or mile). The unit of measure (km or miles) for the odometer display is not shown in the VFD. The unit of measure for the instrument cluster odometer/trip odometer is selected at the time that it is manufactured, and cannot be changed. The odometer has a RENTAL CAR mode, which will illuminate the odometer information in the VFD whenever the driver side front door is opened with the ignition switch in the OFF or ACCESSORY positions.
During daylight hours (exterior lamps are OFF) the odometer VFD is illuminated at full brightness for clear visibility. At night (exterior lamps are ON), the VFD lighting level is adjusted with the other cluster general illumination lamps using the panel lamps dimmer function of the interior lighting control sleeve on the left multi-function switch control stalk. However, a PARADE mode position of the control sleeve allows the VFD to be illuminated at full brightness if the exterior lamps are turned ON during daylight hours. On vehicles manufactured for domestic markets, the odometer VFD is also illuminated at full brightness whenever the Malfunction Indicator Lamp (MIL) indicator is illuminated, and cannot be dimmed until the MIL indicator is extinguished.
The CCN module for this vehicle is serviced only as a complete unit. The CCN module cannot be adjusted or repaired. If a gauge, an LED unit, a VFD unit, the electronic circuit board, the circuit board hardware, the cluster overlay or the cluster housing are damaged or ineffective, the entire CCN module must be replaced. The cluster lens and the cluster hood and mask unit are available for separate service replacement.