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 for 3 seconds:

    • The ABS indicator
    • The battery indicator
    • The BRAKE indicator
    • The change engine oil indicator
    • The check gages indicator
    • The LOW FUEL indicator
    • The park brake indicator
    • The reduced engine power indicator
    • The security indicator
    • The tire pressure low indicator
    • The traction disabled indicator
    • All gages sweep to their minimum physical position and then to their actual physical position.

The following indicators illuminate for the specified times:

    • The AIR BAG indicator flashes 7 times.
    • The seat belt indicator illuminates for 20 seconds followed by 55 seconds of flashing with the drivers seat belt unfastened, or, the seat belt indicator will illuminate for 8 seconds with the drivers seat belt fastened.
    • The SERVICE ENGINE SOON indicator (MIL) illuminates briefly.
    • All message center segments illuminate briefly.

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 powertrain control module (PCM). The IPC receives a class 2 message from the PCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 40°C (100°F) or below if:

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

Engine Oil Pressure Gage

The IPC displays the engine oil pressure as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the engine oil pressure. The engine oil pressure gage defaults to 0 kPa (0 psi) or below if:

    • The PCM detects a malfunction in the engine oil pressure sensor circuit.
    • The IPC detects a loss of class 2 communications with the PCM.

Fuel Gage

The IPC displays the fuel level as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the fuel level percent. The fuel gage defaults to empty if:

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

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

Odometer

The base IPC contains a season odometer and a trip odometer. The uplevel IPC contains a season odometer and 2 trip odometers. Momentarily press the trip/reset switch on the IPC in order to toggle between the season odometer and the trip odometer. Press the trip/reset switch for greater than 2 seconds, while the trip odometer is displayed, in order to reset the trip odometer.

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. The odometer displays either miles or kilometers as requested by the activation of the Personalization button on the steering wheel controls.

PRND321 Display

The IPC displays the selected gear position as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the gear position. The PRND321 display blanks if:

    • The PCM detects a malfunction in the transmission range switch circuit.
    • The IPC detects a loss of class 2 communications with the PCM.

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 4,000 pulses/mile signal. The IPC uses the vehicle speed signal circuit (4,000 pulses/mile) from the PCM in order to calculate the vehicle speed. If the IPC detects a malfunction in the vehicle speed signal circuit, the IPC uses the class 2 message from the PCM indicating the vehicle speed.

Tachometer

The IPC displays the engine speed based on the 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 (2 pulses/engine revolution) from the PCM in order to calculate the engine speed. If the IPC detects a malfunction in the engine speed signal circuit, the IPC uses the class 2 message from the PCM indicating the engine speed.