Vacuum-Fluorescent Displays

WARNING: This page is about a different car, the 2016 Jeep Wrangler and 2015 Jeep Wrangler. However, it is still accessible from the selected car via links, so may be relevant.

With the ignition switch in the OFF or ACCESSORY positions the Vacuum-Fluorescent Display (VFD) displays are activated and the total odometer information is displayed when the driver door is opened (Rental Car Mode) and are deactivated when the driver door is closed. Otherwise, both display units are 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 CCN circuitry controls the VFD and provides the following features:

Odometer/Trip Odometer Display Toggling - Actuating the odometer/trip odometer push button momentarily with the ignition switch in the ON position will toggle the odometer VFD between the odometer and trip odometer modes. Depressing the odometer/trip odometer push button for about two seconds while the VFD is in the trip odometer mode will reset the trip odometer value to zero. Holding the odometer/trip odometer push button depressed while turning the ignition switch from the OFF position to the ON position will initiate the instrument cluster self-diagnostic test. Refer to DIAGNOSIS AND TESTING for additional details. The CCN microcontroller remembers which odometer display mode is active when the ignition switch is turned to the OFF position, and returns the display to that mode when the ignition switch is turned ON again
Trip Odometer Reset - When the trip odometer reset switch button is pressed and held for longer than about two seconds with the ignition switch in the ON or START positions, the trip odometer will be reset to 0.0 kilometers (miles). The VFD must be displaying the trip odometer information in order for the trip odometer information to be reset.
GasCap Message Display - On vehicles manufactured with a United States country code, each time the cluster receives an electronic message from the PCM indicating a monitored leak in the evaporative emissions system, the cluster replaces the displayed odometer/trip odometer value with the textual message, gascap . This message serves as a reminder to the vehicle operator to check that the gas cap is properly installed and tightened, but could also indicate another source of air leakage in the on-board evaporative and vapor recovery emissions systems. Unless the leak is corrected, this message will latch and remain displayed during the current and each subsequent ignition cycle until the trip odometer reset button is pressed and released momentarily, which will revert the display to the odometer/trip odometer information that was last displayed for the remainder of that ignition cycle. Once the source of a leak has been corrected, either momentarily pressing the trip odometer reset button or cycling the ignition switch will unlatch the message and return the odometer/trip odometer to normal operation.
Communication Error - If the cluster fails to receive an electronic distance message during normal operation, it will hold and display the last data received until the ignition switch is turned to the OFF position. If the cluster does not receive a distance message within one second after the ignition switch is turned to the ON position, it will display the last distance value stored in the cluster memory. If the cluster is unable to display odometer information due to an error internal to the cluster, the VFD will display error .

The PCM continually monitors the vehicle speed pulse information received from the wheel speed sensors, then sends the proper messages to the CCN. For proper diagnosis of the wheel speed sensors, the PCM, the CCN, the CAN data bus or the electronic communication related to odometer/trip odometer operation a diagnostic scan tool is required. Refer to the appropriate diagnostic information.

Proper testing of the CAN or LIN 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.