Vacuum-Fluorescent Display

The Vacuum-Fluorescent Display (VFD) unit is soldered to the CCN electronic circuit board. With the ignition switch in the Off or Accessory positions, the odometer display is activated when the driver door is opened and is deactivated when the driver door is closed. Otherwise, the display unit is active when the ignition switch is in the On or Start positions, and inactive when the ignition switch is in the Off or Accessory positions.

The illumination intensity of the VFD unit is controlled by the CCN circuitry based upon an input from the headlamp switch and a dimming level input received from the panel dimmer switch. The CCN synchronizes the illumination intensity of other VFD units with that of the unit in the CCN by sending electronic dimming level messages to other electronic modules in the vehicle over the CAN/LIN data bus.

The CCN VFD unit has several display capabilities including odometer, trip odometer, engine hours, gear selector indication (PRNDL) for models with an automatic transmission, several warning or reminder indications, and various diagnostic information when certain fault conditions exist. An odometer/trip odometer switch on the CCN circuit board is used to control some of the display modes. This switch is actuated manually by depressing the odometer/trip odometer switch button that extends through the lower edge of the cluster lens, just left of the tachometer. Actuating this switch momentarily with the ignition switch in the On position will toggle the VFD between the odometer and trip odometer modes. Depressing the switch button for about two seconds while the VFD is in the trip odometer mode will reset the trip odometer value to zero.

Holding this switch depressed while turning the ignition switch from the Off position to the On position will initiate the CCN self-diagnostic actuator test. Refer to the instrument cluster diagnosis and testing service information for additional details on this cluster function. The CCN microprocessor remembers which display mode is active when the ignition switch is turned to the Off position, and returns the VFD display to that mode when the ignition switch is turned On again.

The VFD unit is diagnosed using the CCN self-diagnostic actuator test. (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING)  and DIAGNOSIS AND TESTING . Proper testing of the CAN data bus and the electronic data bus message inputs to the CCN that control some of the VFD functions requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information. Specific operation details for the odometer, the trip odometer, the gear selector indicator and the various warning and reminder indicator functions of the VFD unit may be found elsewhere in this service information.