GM Service Manual Online
For 1990-2009 cars only

The driver information center (DIC) displays important vehicle information when it first powers up. The DIC is also used to display odometer information when other important vehicle information is not being displayed. The odometer information is transmitted to the instrument panel cluster (IPC) over GMLAN for display in the DIC. The body control module (BCM) is responsible for reading the season odometer information. The DIC switches are analog switches that use the resistor ladder setup to relay the button press information. The DIC switch resistor ladder consists of 1.27 K ohm for the INFO switch and a 715 ohm for the Reset/Select switch. A 4.22 K ohm pull-up resistor to ignition is the analog input and it is internal to the IPC. The IPC reads the voltages and by comparison of the voltage level determines which switch is pressed. The switch input to the cluster is normally open and is at the reference voltage.

There are 2 DIC buttons on the IPC:

    • INFO
    • RESET/SELECT

The 2 DIC buttons however provide 3 switch functions. Pressing the INFO and RESET/SELECT button at the same time provides the MENU switch function.

INFO

The INFO button is used in order to navigate through the following driver information center (DIC) information modes:

    • AV VEHICLE SPEED
    • AV FUEL ECON
    • COOLANT TEMPERATURE
    • FUEL RANGE
    • OIL LIFE MONITOR
    • TRIP ODOMETER A
    • TRIP ODOMETER B
    • BOOST (Turbo Only

Other instrument panel cluster (IPC) information displayed in the DIC are Season odometer and Outside Air Temp.

AV VEHICLE SPEED

Average speed is calculated using the equation: Average Speed = Distance/Ignition On

    • Distance = The accumulated distance travelled since the last reset of this value
    • Ignition On = The accumulated ignition on time since the last reset of this value

Ignition ON time is measured from the time that the ignition is turned ON to the time when the ignition is turned OFF. The value of this mode is retained during ignition OFF. Press and hold the RESET/SELECT button on the DIC for 1 second in order to reset the average speed display.

FUEL RANGE

This message indicates the estimated distance that the vehicle can travel under the current fuel economy and fuel level conditions since the last reset of the value. Fuel Range is calculated using the equation: Fuel Range = Distance Sum/Fuel Sum

    • Distance Sum = The accumulated distance travelled since the last reset of this value
    • Fuel Sum = The accumulated fuel delivered since the last reset of this value

The DIC receives a serial data message from the body control module (BCM) regarding fuel usage information. The value of this mode is retained during ignition OFF and can be changed between English units and metric units. Press and hold the RESET/SELECT button on the DIC switch for 1 second in order to reset the ECON display.

COOLANT TEMPERATURE

The DIC receives GMLAN serial data message from the BCM requesting the display of the coolant temperature. The coolant temperature is sent to the BCM as determined by the engine control module (ECM) via GMLAN serial data message.

FUEL RANGE

This message indicates the estimated distance that the vehicle can travel under the current fuel economy and fuel level conditions since the last reset of the value. Fuel Range is calculated using the equation: Fuel Range = Distance Sum/Fuel Sum.

    • Distance Sum = The accumulated distance travelled since the last reset of this value.
    • Fuel Sum = The accumulated fuel delivered since the last reset of this value

The DIC receives a GMLAN serial data message from the BCM with fuel information. The value of this mode is retained during ignition OFF and can be changed between English units and metric units. The FUEL RANGE display cannot be reset.

OIL LIFE MONITOR

The ECM sends the oil life remaining percentage to the body control module (BCM) via a GMLAN serial data message. The DIC receives a serial data message from the BCM indicating the remaining oil life. The DIC displays the current percentage of the GM Oil Life System as determined by the ECM.

TRIP ODOMETER A and TRIP ODOMETER B

The DIC displays vehicle trip odometer mileage based on the vehicle speed signal (VSS) from the body control module (BCM). The trip odometer displays accumulated km (mi) since the last reset of this value. The trip odometer is capable of displaying up to 999.9 km (999.9 mi). Trip odometer information is not retained when the battery is disconnected. Press and hold the INFO button on the DIC for 1 second in order to reset the trip odometer display.

BOOST (Turbo Only)

The DIC displays the amount of boost available to the engine based on the engine boost serial data message from the ECM. The ECM sends the engine boost data to the BCM. The BCM transmitts the data over GMLAN serial data circuit to the IPC for display in the DIC. Scroll through the DIC information menus until boost is displayed. The BOOST menu shows a graphic that indicates the amount of boost the engine is receiving in either pounds per square inch (psi) or kilopascals (kPa). Refer to Turbocharger System Description or Boost Control System Description

RESET/SELECT

The RESET/SELECT button is used in order to acknowledge a warning message, reset an option, or to select an option. Press and hold for 0.25 second to perform RESET/SELECT.

MENU

The MENU button is used in order to navigate through the following personalization modes:

    • AUTO UNLK
    • DELAY LOCK
    • EXT LIGHTS
    • LANGUAGE
    • LIGHT FLASH
    • LOCK HORN
    • OIL-LIFE RESET
    • REMOTE START
    • SECURITY
    • UNITS
    • UNLOCK HORN

OIL-LIFE RESET

The engine control module (ECM) sends the oil life remaining percentage to the body control module (BCM) via a GMLAN serial data message. The driver information center (DIC) receives a GMLAN serial data message from the BCM indicating the remaining oil life. The DIC displays the current percentage of the GM Oil Life System as determined by the ECM. When the oil life remaining percentage drops below 10 percent, the DIC displays CHANGE ENGINE OIL. When the engine oil is changed, reset the engine oil life in order to clear the oil life remaining percentage display. Press and hold the RESET/SELECT button for 5 seconds until the DIC acknowledges.

Odometer

The odometer information is stored in the body control module (BCM) and is transmitted to the instrument panel cluster (IPC) for display in the driver information center (DIC). The IPC stores a backup copy of the odometer value in case the IPC does not receive a valid odometer reading form the BCM. The last known good odometer value from the BCM is displayed by the IPC before ERROR is displayed in the DIC.

Indicators and Warning Messages

For more information on driver information center (DIC) warning messages, refer to Indicator/Warning Message Description and Operation .