GM Service Manual Online
For 1990-2009 cars only

Displays Test

Certain instrument panel cluster (IPC) features are tested when the ignition is turned on in order to verify the features are working properly. The following indicators illuminate briefly at key up unless otherwise noted:

    • ABS
    • Air bag - flashes 7 times
    • Brake system
    • Charging system
    • Check oil
    • Door ajar
    • Engine coolant temperature
    • Fasten safety belt
    • Low engine coolant level
    • Low fuel
    • Low washer fluid
    • Malfunction Indicator Lamp (MIL)
    • Service vehicle soon
    • Theft system

Indicators and Warning Messages

Refer to Indicator/Warning Message Description and Operation .

Engine Coolant Temperature Gage

The IPC displays the engine coolant temperature as determined by the PCM. The body control module (BCM) receives a class 2 message from the PCM indicating the engine coolant temperature. The BCM converts the engine coolant temperature into a percent gage deflection. The IPC receives a message from the BCM via the serial peripheral interface (SPI) indicating the requested gage position. The engine coolant temperature gage defaults to 38°C (100°F) or below if:

    • The PCM detects a malfunction in the engine coolant temperature sensor circuit.
    • The BCM detects a loss of class 2 communications with the PCM.
    • The IPC detects a loss of SPI communications with the BCM.

Fuel Gage

The IPC displays the fuel level as determined by the PCM. The body control module (BCM) receives a class 2 message from the PCM indicating the fuel level percent. The BCM converts the fuel level percent into a percent gage deflection. The IPC receives a message from the BCM via the serial peripheral interface (SPI) indicating the requested gage position. The fuel gage defaults to E (empty) if:

    • The PCM detects a malfunction in the fuel level sensor circuit.
    • The BCM detects a loss of class 2 communications with the PCM.
    • The IPC detects a loss of SPI communications with the BCM.

When the fuel level is less than a pre-determined value, the low fuel indicator illuminates.

Odometer

The IPC contains a season odometer and a trip odometer. Momentarily press the trip/reset switch on the IPC in order to toggle between the season odometer and the trip odometer. In order to reset the trip odometer, press the trip/reset switch for greater than 2 seconds. The IPC calculates the mileage based on the vehicle speed signal circuit from the PCM. The odometer will display 'error' if an internal IPC memory failure is detected.

Speedometer

The IPC displays the vehicle speed based on the information from the PCM. The PCM converts the data from the vehicle speed sensor to a 4000 pulses/mile signal. The IPC uses the vehicle speed signal circuit of 4000 pulses/mile from the PCM in order to calculate the vehicle speed. The speedometer defaults to 0 km/h (0 mph) if a malfunction in the vehicle speed signal circuit of 4000 pulses/mile exists or if the BCM sends or receives invalid data with the IPC via serial peripheral interface (SPI).

Tachometer

The IPC displays the engine speed based on information from the PCM. The PCM converts the data from the engine speed sensor to a 2 pulses/engine revolution signal. The IPC uses the engine speed signal circuit of 2 pulses/engine revolution from the PCM in order to calculate the engine speed. The tachometer defaults to 0 rpm if a malfunction in the engine speed signal circuit of 2 pulses/engine revolution exists or if the BCM sends or receives invalid data with the IPC via serial peripheral interface (SPI).