GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2001 🢒 Century 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Instrument Cluster Description and Operation

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:

    • Antilock brake system
    • Air bag (flashes 7 times)
    • Brake system
    • Change oil soon
    • Charging system
    • Engine coolant temperature
    • Low coolant level
    • Low engine oil level
    • Low engine oil pressure
    • Low fuel
    • Low traction
    • Low tire pressure
    • Low washer fluid
    • Malfunction indicator lamp (MIL)
    • Security
    • Service vehicle soon

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 IPC receives a class 2 message from the PCM indicating the engine coolant temperature. The engine coolant temperature gage defaults to C 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.

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 14% (84ohms), the low fuel indicator illuminates.

Odometer

The IPC contains a season odometer and a trip odometer. Momentarily press the trip select/reset switch in order to toggle between the season odometer and the trip odometer. Press the trip select/reset switch for greater than 1.5 seconds, while the trip odometer is displayed, in order to reset the trip odometer. The IPC displays the vehicle mileage and trip mileage as determined by the IPC. The IPC calculates the mileage based on the vehicle speed information from the PCM. The odometer will display 'error' if an internal IPC memory failure is detected.

PRNDL 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 PRNDL display shall flash all gear positions 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 4000 pulses per mile signal. The IPC uses the vehicle speed signal circuit from the PCM in order to calculate the vehicle speed. The speedometer defaults to 0 mph (0 kph) if a malfunction in the vehicle speed sensor circuit exists.

Tachometer

The IPC displays the engine speed as determined by the PCM. The IPC receives a class 2 message from the PCM indicating the engine speed. The tachometer will default to 0 rpm if:

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