Operation CHARM: Car repair manuals for everyone.
Home >> Dodge or Ram Truck >> 2012 >> Ram Cargo Van V6-3.6L >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Instrument Cluster / Carrier >> Description and Operation >> Instrument Cluster - Description

Instrument Cluster - Description






DESCRIPTION - LHD





The instrument cluster (1), located in the instrument panel above the steering column is only visible through an opening in the instrument panel top cover (2). The main body of the instrument cluster, including the mounts and the electrical connections, are concealed within the instrument panel. The instrument cluster for this vehicle also includes the hardware and software necessary to serve as the electronic body control module known as the Cab Compartment Node or (CCN).

Besides analog gauges and indicators, the instrument cluster incorporates one of two available 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 larger fixed segment VFD display unit is an Electronic Vehicle Information Center (EVIC) that is re-configurable. 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. For more information on the EVIC Description and Operation

The instrument cluster gauges and indicators are visible through dedicated openings in the cluster mask and are protected by a clear plastic cluster lens. Integral latch formations on the lens secure it to the cluster lens, hood and mask unit to the cluster housing. 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 cluster has four integral mounting tabs, one on each upper and lower corner of the housing. The cluster is secured to the instrument panel support structure by screws through these mounting tabs.

The rear of the cluster housing and the CCN electronic circuitry are protected by a molded black plastic rear cover (1), which is also secured to the cluster housing by integral latch features. The rear cover includes clearance holes for the cluster connector receptacles. The connector receptacles on the back of the cluster electronic circuit board connect the CCN to the vehicle electrical system through dedicated take outs and connectors of the instrument panel wire harness.

The cluster overlay is a laminated plastic unit. The visible, outer surface of the overlay is marked with all of the gauge dial faces and graduations, but this layer is also translucent. 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, on vehicles so equipped, the LED general illumination lamps behind it to be visible through the outer layer of the overlay through predetermined stencil-like cutouts.

Several versions of the CCN module are offered on this vehicle. These versions accommodate not only the different car lines, but also 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.

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, or the cluster housing are damaged or ineffective, the entire CCN module must be replaced. Some of the components for the instrument cluster used in this vehicle are serviced individually. The cluster lens, hood and the mask unit can be serviced separately as a one piece assembly.

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:

- Accessory Power Delay Relay Control - The CCN provides operating control of the accessory power delay relay.
- 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, 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.
- 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 multiplexed hard-wired inputs from the headlamp switch on the instrument panel as well as electronic headlamp dimmer switch status and turn signal switch status messages from the Steering Control Module (SCM) integral to the multi-function switch on the left side of 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.
- Heated Seat Actuation Signal - Where used, the CCN controls the heated seat system request input by transferring the request across the bus to the Heated Seat Module.
- Horn Switch Support - On clusters equipped with a EVIC display, the CCN receives electronic horn switch status messages from the Steering Control Module (SCM) integral to the multi-function switch on the left side of the steering column over the LIN data bus and transmits the appropriate electronic horn request messages over the CAN data bus to support the horn function. On instrument clusters that are non EVIC equipped, the horn switch is hard-wired to the CCN and the CCN will transmit the messages over the LIN data bus.
- 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 hardwired inputs from the headlamp switch, the reading lamp switches, the Wireless Ignition Node (WIN) 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 module, the Heated Seat Module (HSM), the instrument panel switch pod, the Steering Wheel Switch Module (SWSM) and the SCM, then either acts on that information directly or places electronic messages on the CAN data bus for use by other electronic modules.
- Panel Lamps Dimming Control - The CCN monitors multiplexed hard-wired inputs from the panel lamps dimmer switch thumbwheel in the headlamp switch, 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.
- Remote Radio Switch Interface - On clusters equipped with a EVIC display, the CCN monitors electronic message inputs from the optional remote radio switches over the LIN data bus, then provides the appropriate electronic data bus messages to the radio to select the radio or optional hands-free cellular system operating mode, volume control, preset station scan and station seek features. On instrument clusters that are non EVIC equipped, the remote radio switches are hard-wired directly to the CCN and the CCN will transmit the messages over the LIN data bus.
- UConnect(TM) Hands-Free Voice Actuated Communication System Actuation Signal - Where used, the CCN controls the UConnect(TM) system actuation signals.
- Vehicle Theft Security System Control - The CCN monitors inputs across the BUS to provide electronic horn and lighting request signals to the TIPM for the appropriate VTSS alarm output features.
- Wiper and Washer Switch Support - The CCN monitors electronic wiper switch and washer switch status messages from the SCM integral to the multi-function switch on the left side of 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




Figure 2 - High Line with EVIC




The CCN includes the following Vacuum-Fluorescent Displays (VFDs):

- Odometer and Gear Selector Indicator Displays (21) - includes Cruise indicator.
- Compass Mini-Trip Computer (23) - optional except Chrysler and Dodge base clusters
- Electronic Vehicle Information Center Display (18) - optional

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 to the right of the odometer VFD. 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.

The CCN provides support for the optional CMTC by calculating average fuel economy, distance to empty and outside temperature values and storing trip odometer and elapsed ignition-ON time data. The CCN receives data and reset requests from the CMTC switches and displays the appropriate information in the CMTC VFD unit.

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.

During daylight hours (exterior lamps are OFF) the VFDs are 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 thumbwheel of the headlamp switch on the instrument panel. However, a PARADE mode position of the thumbwheel allows the VFD to be illuminated at full brightness if the exterior lamps are turned ON during daylight hours.

pro multis · About Operation CHARM