GM Service Manual Online
For 1990-2009 cars only

Trip Mode Display

The driver information display calculates and displays the following vehicle parameters:

    • Average fuel economy
    • Instant fuel economy
    • Trip range
    • Fuel used
    • Average Speed

Only one of the above parameters will display at a time. The operator may change the parameter displayed by depressing the MODE button. The MODE button is located on the display face. The operator may change the display units from English to metric units by pressing the E/M button on the display face.

The driver information display performs the following error detection where possible:

    • No serial data stream for 10 seconds
    • An open-circuited fuel level sender

If the driver information display is unable to calculate a value due to a missing speed signal, an E displays when any of the following functions is selected:

    • AVG ECON
    • INST ECON
    • AVG SPEED

In the absence of vehicle communications, a double dash (--) displays in the digits section. The display format for each mode is indicated in the following table:

Parameter

Update Range

Range

Reset Value

Units

Instant Fuel Economy

1 second

0-99

N/A

MPG or L/100 km

Average Fuel Economy

2 seconds

0.0-99.9

0.0

MPG or L/100 km

Average Speed

2 seconds

0.0-99.9

0.0

MPH or km/h

Fuel Used

0.1 Gal/L

0.0-999

0.0

G or L

Trip Range

8 seconds

40-000 (LO,40)

N/A

miles or km

Reset Operation

In order to reset the driver information display, simultaneously press the following buttons for at least 2 seconds:

    • MODE
    • ENGLISH/METRIC

The reset is acknowledged with the display showing all segments ON for 1 second. You may only reset the following modes. The reset affects all 3 of these modes simultaneously:

    • AVG ECON
    • FUEL USED
    • AVG SPEED

Average Economy

Average fuel economy (AFE) is calculated as the ratio between the following values:

    • The accumulated distance since the last AFE reset
    • The accumulated fuel consumption since the last AFE reset

After a trip reset, the AFE resets both the accumulated distance and the accumulated fuel consumption. The driver information display retains the AFE value during ignition OFF.

Instant Fuel Economy

Instantaneous fuel economy is the ratio between the following values:

    • The accumulated distance gathered over the past 1 second
    • The accumulated fuel consumption over the past 1 second

You cannot reset the instant fuel economy mode. The value of this mode is not retained during ignition OFF.

Trip Range

Trip Range is calculated as the product of the average fuel economy (AFE) multiplied by the amount of fuel remaining in the tank. When a range of less than 40 miles is calculated, the low-fuel-range mode is entered. During the low-fuel-range mode, the numeric display will spell LO. Performing a reset will have no effect while in trip-range mode. If the AFE is reset, the trip range will not be affected until after a few hours of new AFE data is obtained.

Fuel Used

The drive information display calculates and displays the total amount of fuel used since the last reset operation. This information is accumulated from liters of fuel over real time, converted to gallons as required. Simultaneously pressing the following buttons while in the fuel-used display mode resets the fuel-used accumulator to zero:

    • MODE
    • ENGLISH/METRIC

The value of this mode is retained during ignition OFF.

Average Speed

Average speed is the ratio of the accumulated distance over accumulated ignition on-time. Both values are calculated since the last average speed reset. On-time is the accumulation of all on-time cycles since the last reset. An on-time cycle is measured from the time that the ignition is turned ON, to the time when the ignition is turned OFF. Simultaneously pressing the following buttons resets the average speed and returns the setting to zero.

    • MODE
    • ENGLISH/METRIC

The value of average speed is retained during an ignition OFF.

Compass Display

The compass display circuitry is entirely contained within the driver information display. Refer to DIC or Message Center Operation for information on the following functions:

    • Initiating the compass self-calibration function
    • Setting the variance

Temperature Display

The driver information display applies voltage to the ambient air temperature sensor. The ambient air temperature sensor is a thermister (the temperature and the resistance vary inversely):

    • As the resistance of the ambient air temperature sensor increases, the driver information display senses a larger voltage drop across the ambient air temperature sensor, indicating a lower temperature.
    • As the resistance of the ambient air temperature sensor decrease, the driver information display senses a smaller voltage drop across the ambient air temperature sensor, indicating a higher temperature.

If the temperature is below 3°C (38°F) the temperature digits will toggle between displaying the following items for 2 minutes:

    • The outside temperature
    • The word ICE

This condition will occur once per ignition cycle.

The driver information display uses the vehicle speed signal from the powertrain control module (PCM) in order to determine when to update the temperature display with a new outside air temperature reading. The vehicle must be driven over 16 km/h (10 mph) before the temperature display will be updated. For more information on temperature display operation, refer to Electronic Compass.

Dimming Control

Display dimming for the trip calculator follows the radio dimming characteristics. Upon activation of the parklamps, the display steps from dim to maximum brightness while in the dim mode. Further dimming is controlled by the PWM Dimming Signal of the IP dimming control. The display goes blank upon lowest dimming request of the dimming control.