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 occurs at key up:

    • The air bag indicator flashes 8 times.
    • The ABS indicator illuminates briefly.
    • The check engine indicator (MIL) illuminates briefly.
    • The brake indicator illuminates briefly.
    • All gages sweep.
    • The head up display (HUD) illuminates all segments briefly.
    • The security indicator illuminates briefly.
    • The traction indicator illuminates briefly.
    • The tire inflation monitor indicator illuminates briefly.
    • The seat belt indicator illuminates.
    • The MPH or KM/H indicator illuminates.
    • The driver information center (DIC) displays XLR briefly and then it will display the last item before key OFF.
    • The audible warning chimes 6 times.

Indicators and Warning Messages

Refer to Indicator/Warning Message Description and Operation.

Engine Coolant Temperature Gage

The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the engine control module (ECM). The IPC receives a serial data messages from the ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to the gage lowest position or below if:

    • The ECM detects a malfunction in the engine coolant temperature sensor circuit.
    • The IPC loses serial data communication from the ECM.

Engine Oil Pressure Gage

The instrument panel cluster (IPC) displays the engine oil pressure as determined by the engine control module (ECM). The IPC receives serial data messages from the ECM indicating the engine oil pressure. The engine oil pressure gage defaults to 0 kPa (0 psi) or below if:

    • The ECM detects a malfunction in the engine oil pressure sensor circuit.
    • The IPC loses serial data communication from the ECM.

Fuel Gage

The instrument panel cluster (IPC) displays the fuel level as determined by the engine control module (ECM). The IPC receives serial data messages from the ECM indicating the fuel level percent. The fuel gage defaults to empty if:

    • The ECM detects a malfunction in the fuel level sensor circuit.
    • The IPC loses serial data communication from the ECM

Speedometer

The instrument panel cluster (IPC) displays the vehicle speed based on information from the vehicle speed signal circuit. The engine control module (ECM) converts the data from the vehicle speed sensor to a 4,000 pulses/mile signal. The vehicle speed signal circuit is pulled up to controlled battery voltage in the IPC. The IPC uses the vehicle speed signal circuit from the ECM in order to calculate the vehicle speed. The speedometer defaults to 0 km/h (0 mph) when a malfunction in the vehicle speed signal circuit exists. The speedometer displays either miles or kilometers as requested by the activation of the English/metric setting on the driver information center (DIC). The associated indicator, MPH or KM/H illuminates in the IPC. The speedometer range is 0-160 mph or 0-260 km/h.

Tachometer

The instrument panel cluster (IPC) receives a discrete input from the engine control module (ECM) indicating the engine speed. The engine speed signal circuit is pulled up to controlled battery voltage in the IPC. Each engine revolution represents 2 input pulses to the ECM. The instantaneous engine speed is calculated by the ECM using the time difference between the 2 input pulses. The tachometer will default to 0 RPM if the ignition is in OFF, ACCESSORY, or CRANK

Volt Gage

The instrument panel cluster (IPC) displays the battery voltage as detected by the BCM. The BCM sends a serial data message to the IPC indicating the vehicle battery voltage. The voltage is also displayed in the DIC. The DIC displays high or low voltage when the IPC detects voltage levels out of the normal operating range. The DIC issues the appropriate warning message.