Meters
ODOMETERAn odometer and trip odometer are standard equipment in all instrument clusters. The odometer and trip odometer information are displayed in a common electronic Vacuum Fluorescent Display (VFD), which is visible through a small window cutout located in the lower left quadrant of the instrument cluster overlay. However, 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 knob that extends through the lower edge of the cluster lens, just right of the odometer VFD. When the trip odometer information is displayed, the word "TRIP" is also illuminated in a green color and at the same lighting level as the trip odometer information in the lower right corner of the VFD. Both the odometer and the trip odometer information is stored in the instrument cluster memory.
The odometer can display values up to 499,999 kilometers (499,999 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 have a decimal point and will not show values less than a full unit (kilometer or mile), the trip odometer display does have a decimal point and will show tenths of a unit (kilometer or mile). The unit of measure (kilometers or miles) for the odometer and trip 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. During daylight hours (exterior lamps Off) the VFD is illuminated at full brightness for clear visibility. At night (exterior lamps are ON) the VFD lighting level is adjusted with the other cluster illumination lamps using the panel lamps dimmer knob of the headlamp switch. However, a "Parade" mode position of the panel lamps dimmer knob allows the VFD to be illuminated at full brightness while the exterior lamps are turned ON during daylight hours. The VFD, the trip odometer switch, and the trip odometer switch button are serviced as a unit with the instrument cluster.
The odometer and trip odometer give an indication to the vehicle operator of the distance the vehicle has traveled. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Chrysler Collision Detection (CCD) data bus. The odometer and trip odometer information is displayed by the instrument cluster Vacuum Fluorescent Display (VFD), and the VFD will not display odometer or trip odometer information after the ignition switch is turned to the OFF position. The instrument cluster circuitry controls the VFD and provides the following features:
* Odometer/Trip Odometer Display Toggling- Actuating the trip odometer reset switch momentarily with the ignition switch in the ON position will toggle the VFD between the odometer and trip odometer display. Each time the ignition switch is turned to the ON position the VFD will automatically return to the mode (odometer or trip odometer) last displayed when the ignition switch was turned to the OFF position.
* Trip Odometer Reset - When the trip odometer reset switch is pressed and held for longer than about two seconds, the trip odometer will be reset to 000.0 kilometers (miles). The VFD must be displaying the trip odometer information in order for the trip odometer information to be reset.
* Message Failure - If the cluster fails to receive a distance message during normal operation, it will flash the odometer/trip odometer distance information ON and OFF repeatedly until a distance message is received, or until the ignition switch is turned to the OFF position, whichever occurs first. 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 message stored in the cluster memory. If the cluster is unable to display distance information due to an error internal to the cluster, the VFD display will be blank.
* Actuator Test - Each time the cluster is put through the actuator test, the VFD will display all of its characters at once, then step through each character segment individually during the VFD portion of the test to confirm the functionality of the VFD and the cluster control circuitry.
The PCM continually monitors the vehicle speed sensor, then sends the proper distance messages to the instrument cluster. For further diagnosis of the odometer/trip odometer or the instrument cluster circuitry that controls these functions. For proper diagnosis of the vehicle speed sensor, the PCM, the CCD data bus, or the message inputs to the instrument cluster that control the odometer/trip odometer, a DRB III scan tool is required Refer to the appropriate diagnostic information.
SPEEDOMETER
A speedometer is standard equipment on all instrument clusters. The speedometer is located near the center of the instrument cluster overlay. The speedometer consists of a movable gauge needle or pointer controlled by the instrument cluster circuitry and a fixed 210 degree primary scale on the gauge dial face that reads left-to-right either from 0 to 120 mph, or from 0 to 200 km/h, depending upon the market for which the vehicle is manufactured. Each version also has a secondary inner scale on the gauge dial face that provides the equivalent opposite units from the primary scale. Text appearing on the cluster overlay just below the hub of the speedometer needle abbreviates the unit of measure for the primary scale in all upper case letters i.e.: MPH or KM/H), followed by the unit of measure for the secondary scale in all lower case letters (i.e.: mph or km/h). The speedometer graphics are white (primary scale) and blue (secondary scale) against a black field, making them clearly visible within the instrument cluster in daylight. When illuminated from behind by the panel lamps dimmer controlled cluster illumination lighting with the exterior lamps turned ON, the white graphics appear blue-green and the blue graphics appear blue. The orange gauge needle is internally illuminated. Gauge illumination is provided by replaceable incandescent bulb and bulb holder units located on the instrument cluster electronic circuit board. The speedometer is serviced as a unit with the instrument cluster.
The speedometer gives an indication to the vehicle operator of the vehicle road speed. This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) over the Chrysler Collision Detection (CCD) data bus. The speedometer is an air core magnetic unit that receives battery current on the instrument cluster electronic circuit board through the fused ignition switch output (run-start) circuit whenever the ignition switch is in the ON or Start positions. The cluster is programmed to move the gauge needle back to the low end of the scale after the ignition switch is turned to the OFF position.
The instrument cluster circuitry controls the gauge needle position and provides the following features:
* Message Failure - If the cluster fails to receive a speedometer message, it will hold the gauge needle at the last indication for about four seconds, or until the ignition switch is turned to the OFF position, whichever occurs first. If a new speedometer message is not received after about four seconds, the gauge needle will return to the far left (low) end of the scale.
* Actuator Test - Each time the cluster is put through the actuator test, the gauge needle will be swept to several calibration points on the gauge scale in a prescribed sequence in order to confirm the functionality of the gauge and the cluster control circuitry
The PCM continually monitors the vehicle speed sensor to determine the vehicle road speed, then sends the proper vehicle speed messages to the instrument cluster. For further diagnosis of the speedometer or the instrument cluster circuitry that controls the gauge. For proper diagnosis of the vehicle speed sensor, the PCM, the CCD data bus, or the message inputs to the instrument cluster that control the speedometer, a DRB III scan tool is required. Refer to the appropriate diagnostic information.