The trip calculator calculates and displays (one at a time) the following vehicle parameters:

Important: The numeric display will spell LO FUEL when a range of less than 40 miles is calculated.

The mode indicator next to the corresponding graphics will light. The display is vacuum florescent with 6 characters, 7 segment units, and 7 parameter units. The display format for each mode is indicated in the following table:

The driver information display shows the following indicators:

The information is delivered to the driver through the tell-tale lamps or the indicators. The tell-tale lamps or the indicators illuminate when either a grounding switch is closed or one of the pertinent modules provides a path to ground for the specific indicator. The driver information display does not perform any self-tests or diagnostics and is used only as a communication device for the driver.

The display dimming for the trip calculator follows the radio dimming characteristics. The display step dims to the maximum brightness in the dim mode, when the park lamps are activated. Any further dimming is controlled by the PWM dimming signal of the IP dimming control. The display will go blank upon the lowest dimming request of the dimming control.

Depress the MODE button, located on the trip calculator face, in order to change displayed parameter. Press the ENG/MET button on the face of the trip calculator in order to switch the display units from English to metric.

Important: The ENG/MET state output may be used by other displays in the vehicle in order to set the specific display units. The trip calculator must recall the state of the switch from the last ignition cycle.

The trip calculator performs an error detection when a serial data stream is not present for 10 seconds. If the trip calculator is not able to calculate a value, due to any missing data, the display shows a flashing 0 when the mode is selected. The trip calculator updates the display with the correct information for each mode that is selected within a given time frame. The following table indicates the recommend display rates, the allowable range for each parameter, and the reset values.

The average fuel economy (AFE) is calculated as a ratio between the accumulated distance since the last AFE reset and the accumulated fuel consumption since the last AFE reset (distance/ fuel used).

The AFE will zero out both the accumulated distance and the accumulated fuel consumption under the following conditions:

The trip calculator must retain the AFE when the ignition is OFF.

The trip calculator calculates and displays the total amount of fuel used since the last reset. The fuel used is accumulated from liters of fuel over real time converted into gallons or liters, as needed. Press the reset button while in the fuel used display mode in order to reset the fuel used accumulator to zero. If the amount of fuel used since the last reset is greater than 99.9 gallons (378 liters), 99.9 will continue to display until the next reset.

The range is calculated as the product of the average fuel economy (AFE) multiplied by the amount of fuel that is remaining in the tank (AFE times the fuel remaining). When a range of less than 40 miles is calculated, the low fuel range mode is entered, except during the first 10 miles following the AFE reset. During the first 10 miles, the low fuel range (LO FUEL message) will not be entered and the range of the values will be 0-999.

The numeric display will spell LO FUEL and extinguish the MI or km units during the low fuel range mode. After the low fuel range mode is first entered, the message will flash at a rate of 2 Hz for 60 seconds. The message will be displayed continuously after the initial 60 second period. If the range mode was not selected when the low fuel range mode was entered, the trip calculator overrides the mode that is displayed and selects the range mode. Select another mode in order to override the low fuel range mode. If the ignition is cycled the trip calculator will re-enter the mode selection as calculated the first time.

The fuel sender input is a voltage vs. gallons (fuel level) curve generated by a 40-250 ohms variable sender that is located in the fuel tank and pulled up to the ignition in the powertrain control module (PCM). Then, the fuel is sent to the trip computer via UART serial data line communications. The range algorithm must filter the fuel tank sender input over an average period of 2 minutes. The reset button is ineffective while the vehicle is the range mode. The range is reset by an AFE reset.

The trip calculator reads the oil life from the serial data line. The reset button transmits the reset signal back to the powertrain control module (PCM). The trip calculator displays the number received from the PCM. When 0 percent oil life is reached, the trip calculator generates an audible beep and flashes the message for 60 seconds. After the 60 period, the message is displayed continuously. The low oil life mode trip calculator overrides the mode that is displayed, selecting the oil life mode, if the oil life mode was not selected. Select another mode in order to override the low oil life mode. If the ignition switch is cycled, the trip calculator re-enters the mode selection as calculated the first time.

The powertrain control module (PCM) determines the amount of oil life from the various sensors and inputs within the engine control system. When the PCM determines that an oil life of 0% is present, the PCM turns ON the change oil soon indicator by supplying ground to CKT 803.

The boost gauge illuminates per the information that is sent along the serial data line CKT 800. The graphics boost and the light span remains lit as long as the engine is running. The graduations represent 0.6 PSI of the boost and will light if the pressure is equal to or greater than the gradient level. The boost gauge is only used on 3.8 liter supercharged engines.