Vacuum-Fluorescent Display

WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

The Vacuum-Fluorescent Display (VFD) unit is soldered to the EMIC electronic circuit board. With the ignition switch in the Off or Accessory positions, the odometer display is activated when the driver door is opened (Rental Car mode) 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 EMIC circuitry based upon electronic dimming level messages received from the BCM over the PCI data bus, and is synchronized with the illumination intensity of other VFD units in the vehicle. The BCM provides dimming level messages based upon internal programming and inputs it receives from the circuitry of the multi-function switch on the steering column based upon the settings of the control knob and control ring on the left (lighting) control stalk that have been selected by the vehicle operator.

The EMIC VFD unit has several display capabilities including odometer, trip odometer, some warning or reminder indications, and various diagnostic information when certain fault conditions exist. On models equipped with the optional Electronic Vehicle Information Center (EVIC), most of the odometer VFD unit warning and reminder indications are suppressed so as not to duplicate indications that are provided by the EVIC. The odometer VFD warning and reminder messages include:

"door" - indicating a door is ajar (on vehicles without the optional EVIC only).
"gate" - indicating the tailgate is ajar (on vehicles without the optional EVIC only).
"glass" - indicating the tailgate glass is ajar (on vehicles without the optional EVIC only).
"lowash" - indicating that the washer fluid level is low (on vehicles without the optional EVIC only).
"no bus" - indicating there is no PCI data bus communication detected.

An odometer/trip odometer switch on the EMIC 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 right 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 EMIC self-diagnostic actuator test. The VFD will also display the cluster software version level near the completion of the EMIC self-diagnostic actuator test. (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING) for additional details on this cluster function. The EMIC 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 EMIC self-diagnostic actuator test. (Refer to ELECTRICAL/INSTRUMENT CLUSTER - DIAGNOSIS AND TESTING) . Proper testing of the PCI data bus and the electronic data bus message inputs to the EMIC 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, and the various warning and reminder indicator functions of the VFD unit may be found elsewhere in this service information.