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 7 times (not IPC controlled).
    • The ABS indicator illuminates briefly.
    • The battery indicator illuminates briefly.
    • The brake indicator illuminates briefly.
    • The coolant temperature indicator illuminates briefly.
    • The cruise engage indicator illuminates briefly.
    • The engine oil pressure indicator illuminates briefly.
    • The malfunction indicator lamp (MIL) illuminates briefly (not IPC controlled).
    • The seat belt indicator illuminates for 70 seconds or until the driver seat belt is latched (not IPC controlled).
    • The security indicator illuminates briefly.
    • The tire pressure low indicator illuminates briefly.
    • The vehicle dynamics caution (VDC) indicator illuminates briefly.
    • All segments of the driver information center (DIC) illuminate briefly.
    • All odometer segments illuminate briefly.
    • The PRNDL segment illuminates briefly.

Indicators and Warning Messages

Refer to Indicator/Warning Message Description and Operation , Data Link Communications Description and Operation , and Body Control System Description and Operation.

Driver Efficiency Gage (Hybrid)

The IPC displays the driver efficiency as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the fuel efficiency of the vehicle. There are several zones on the gage indicating different levels of efficiency. The gage shall indicate fuel efficiency when the engine is running and will be set at the minimum scale position when the ignition transitions to a mode other than when the engine is running. The gage will default to its half scale position when there is a loss of serial data communication with the ECM

The driver efficiency gage gives feedback to the driver of the hybrid vehicle as to how efficient they are driving. When driving in a way to optimize the fuel economy (e.g. gradually increasing the speed, slow braking, etc.), the pointer or indicator moves into a high efficiency band. When driving in an inefficient manner (e.g.starts, hard braking, constantly changing speeds, etc.), the pointer or indicator moves into a less efficient band. The gage spans several zones, corresponding to different levels of efficiency for acceleration and deceleration. As the indicator moves across the band, the driver receives directional feedback as to whether their driving style is moving towards or away from the desired efficiency.

Engine Coolant Temperature Gage

The IPC displays the engine coolant temperature as determined by the ECM. The IPC receives a serial data message from the ECM indicating the engine coolant temperature. The engine coolant temperature gage defaults to 60°C (140°F) or below if:

    • The ECM detects a malfunction in the engine coolant temperature sensor circuit.
    • The IPC detects a loss of serial data communications with the ECM.
    • The body control module (BCM) detects a loss of serial data communications with the ECM.

Fuel Gage

The IPC displays the fuel level as determined by the ECM. The IPC receives a serial data message 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 detects a loss of serial data communications with the ECM

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

Odometer

The vehicle odometer is calculated and stored electronically in the IPC. The IPC contains a season odometer and trip odometer A or B. Momentarily press the DIC trip/fuel button on the IPC in order to toggle between the season odometer and the trip odometer. Press the DIC set/reset button for greater than 0.25 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 serial data vehicle speed information from the ECM. The odometer will display "error" if an internal IPC memory failure is detected. The odometer displays either miles or kilometers and can be set through the personalization programming menu in the DIC.

PRNDL Display

The IPC displays the selected gear position as determined by the ECM. The IPC receives a serial data message from the ECM indicating the gear position. The PRNDL display blanks if:

    • The ECM detects a malfunction in the transmission range switch circuit.
    • The IPC detects a loss of serial data communications with the ECM.

Speedometer

The IPC displays the vehicle speed as determined by the ECM. The IPC calculates the mileage based on the serial data vehicle speed information from the ECM. The speedometer defaults to 0 km/h (0 mph) if the IPC detects a loss of serial data communications with the ECM.

Tachometer

The IPC displays the engine speed as determined by the ECM. The IPC receives a serial data message from the ECM indicating the engine speed. The tachometer will default to 0 RPM if:

    • The ECM detects a malfunction in the engine speed sensor circuit.
    • The IPC detects a loss of serial data communications with the ECM.

Tachometer (Hybrid)

The hybrid tachometer is a single gage that displays the engine speed and indicates whether the vehicle is in the AUTO STOP or OFF mode of operation. The AUTO STOP mode indicates that the vehicle is still motion capable and the engine could restart by auto start at any time. OFF mode indicates that either the vehicle is turned OFF or the engine has stalled. The instrument panel cluster (IPC) displays the engine speed as determined by the engine control module (ECM). The engine control module (ECM) calculates the engine speed and sends the engine speed serial data message to the BCM. The BCM sends the engine speed via the serial data circuit to the IPC. The tachometer defaults to 0 RPM if:

    • The ECM detects a malfunction in the engine speed sensor.
    • The BCM detects a loss of serial data communication with the ECM.
    • The IPC detects a loss of serial data communication with the BCM.

Battery Gage

The IPC displays the voltage as determined by the regulated voltage control (RVC). The IPC receives a serial data message from the body control module (BCM) indicating the battery voltage. When the engine is ON, the gage should be between 10-16 volts. The gage will default to 0 volts if the IPC detects a loss of communication with the BCM.