Instrument Cluster (Service Information): Description: Description: Notes
The instrument cluster (3) is located in the instrument panel above the steering column opening, directly in front of the driver. The main body of the instrument cluster, including the mounts and the electrical connections, are concealed within the instrument panel below the instrument panel top over (2). The instrument cluster 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 and one optional blue-green digital Vacuum Fluorescent Display (VFD) units. The standard VFD is a fixed segment unit for displaying odometer information, automatic transmission gear selector position (PRNDL), and several other indicators. The optional VFD is a large, reconfigurable display unit which serves as the visual display for the compass, the outside temperature, the trip computer, and 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.
The instrument cluster gauges and Light Emitting Diode (LED) indicators are visible through a dedicated opening in the instrument panel below the cluster hood and are protected by a clear plastic cluster lens (3). Nine integral latch formations on the lens secure it to the cluster hood and mask unit (2) as well as the cluster housing (1). Just behind the cluster lens is the cluster hood and integral mask, which are 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 from the indicator areas and trims the outside perimeter of the cluster overlay. The hood and mask has six 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 (5), 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 LED's 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 as well as the optional reconfigurable display switch button (4) extend from the face of the cluster housing through dedicated holes in the cluster mask and the cluster lens adjacent to their respective VFD units. 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 speedometer and tachometer 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 microcontroller-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. Refer to COMMUNICATION, DESCRIPTION .
The instrument cluster gauges, indicators, VFD units, as well as the cluster illumination are all integral components of the CCN and its electronic circuit board. If any part of the internal working components of the instrument cluster become damaged or ineffective, the entire instrument cluster assembly must be replaced. The cluster lens and the cluster hood and mask unit are the only components of the instrument cluster assembly that can be serviced separately.