Instrument Cluster: Notes
The instrument cluster, Cabin Compartment Node (CCN) is located in the instrument panel above the steering column opening, directly in front of the driver. The remainder of the CCN, including the mounts and the electrical connections, are concealed within the instrument panel behind the cluster bezel. Besides analog gauges and indicators, the CCN 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 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.
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 Front Control Module (FCM) provides timing and control for the accessory power delay relay based upon inputs from the CCN across the Bus and the ignition switch and the door ajar switch inputs to the FCM.
- 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. Refer to DESCRIPTION .
- Automatic Headlamps Control - On models equipped with optional automatic headlamps, the CCN monitors inputs from both the headlamp switch and a sun load sensor located on the top of the instrument panel to provide automatic headlamps.
- Change Oil Indicator A change oil indicator is standard equipment on all instrument clusters built for the US market. On EVIC equipped vehicles, an OIL CHANGE REQUIRED message will appear in the upper portion of the Vacuum Fluorescent Display (VFD) unit. On vehicles not equipped with an optional Electronic Vehicle Information Center (EVIC) option, a CHANGE OIL message will be displayed in the odometer area of the VFD. The change oil indicator message in the odometer area of the VFD will consists of cycling textual CHANGE then OIL messages which appear in place of the odometer/trip odometer information. The EVIC change oil indicator consists of a textual Oil Change Required message that appears within the EVIC VFD
- Enhanced Accident Response Support - The CCN monitors an input from the Occupant Restraint Controller (ORC) 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. The CCN also monitors an input from 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. These Enhanced Accident Response System (EARS) features are each dependent upon a functional vehicle electrical system following the vehicle impact event.
- Exterior Lighting Control - The CCN 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.
- Exterior Lighting Fail-safe - In the absence of a headlamp switch input, the FCM will turn on the cluster illumination lamps and provide electronic headlamp low beam and park lamp request messages. The FCM will also provide default park lamp and headlamp low beam operation and the CCN will turn on the cluster general illumination lighting if there is a failure of the electronic data bus communication between the CCN and the FCM.
- Fuel Level Data Support - The CCN receives fuel used and distance traveled information across the Bus from the PCM and uses this input to calculate the proper fuel gauge needle position and low fuel indicator operation. Based upon this input, the CCN also calculates fuel level, average fuel economy and distance to empty data, then uses electronic messaging to transmit this data over the CAN data bus for use by other electronic modules in the vehicle.
- Heated Seat Control - The CCN monitors hardwire inputs from the heated seat switches. Once the CCN confirms the status of the switch, it will convey a data Bus signal to the Heated Seat Module (HSM) for the request. Once the HSM receives this request, a message will be sent back out on the data Bus to the CCN to actuate the low side driver outputs to the heated seat switch Light Emitting Diode (LED) indicators. The CCN 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. Refer to DESCRIPTION for front seats, or refer to DESCRIPTION for rear seats.
- Interior Lamp Load Shedding - The CCN provides a battery saver feature which will automatically turn off all interior lamps that remain on after a timed interval of about ten minutes as long as the vehicle is not started. If the interior lamps are turned back on during the ten minute time out period, the CCN will alter the time out period to 90 seconds. Should the vehicle be restarted during the time out period, the CCN will revert to the ten minute time out logic.
- Interior Lighting Control - The CCN monitors inputs from the interior lighting switch, the door ajar switches, the reading lamp switches, and the Sentry Key Remote Entry Module (SKREEM) to provide courtesy lamp control. This includes support for timed illuminated entry with theater-style fade-to-off and courtesy illumination defeat features.
- Power Locks - The EMIC monitors inputs from the power lock switches and the Sentry Key Remote Entry Module (SKREEM) to provide control of the power lock motors through high side driver outputs to the motors. This includes support for rolling door locks (also known as automatic door locks), automatic door unlock, briefcase lock mode, door lock inhibit mode. Refer to DESCRIPTION .
- Panel Lamps Dimming Control - The CCN monitors hard wired multiplexed inputs from the headlamp switch on the instrument panel, then provides a hard wired Pulse-Width Modulated (PWM) output that synchronizes the dimming level of all panel lamps dimmer controlled lamps with that of the cluster illumination lighting.
- Remote Radio Switch Interface - The CCN 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. The Radio switches also permit the driver to scroll through, and make selections on the Electronic Vehicle Information Center (EVIC).
- Turn Signal & Hazard Warning Lamp Control - The CCN monitors data Bus messages from the Front Control Module (FCM), then provides electronic turn and hazard lamp illumination. The CCN 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 twenty-four kilometers-per-hour (fifteen miles-per-hour).
- Vacuum Fluorescent Display Synchronization - The CCN monitors buss information from the FCM , then transmits electronic panel lamp dimming level messages which allows all other electronic modules on the CAN data bus with Vacuum Fluorescent Display (VFD) units to coordinate their illumination intensity with that of the CCN VFD units. This includes a parade mode (also known as funeral mode) that allows all VFD units in the vehicle to be illuminated at full (daytime) intensity while driving during daylight hours with the exterior lamps turned On.
- Vehicle Theft Security System Control - The CCN monitors inputs from the door ajar switches, the liftgate ajar switch, the ignition switch, and the Sentry Key Remote Entry Module (SKREEM), 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.
- Rear Wiper/Washer System Control - The CCN monitors both hard wired multiplexed inputs from the rear wiper and washer switches in the multi-function switch on the steering column and electronic messages from the rear wiper and washer switches in the heater and air conditioner control on the instrument panel. The CCN then provides electronic wiper and/or washer request messages to the Front Control Module (FCM) located on the Integrated Power Module (IPM) for the appropriate front or rear wiper and washer system features. Refer to DESCRIPTION .