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:

Refer to Indicator/Warning Message Description and Operation .

The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the powertrain control module (PCM) or the engine control module (ECM). The PCM/ECM sends a GMLAN message to the body control module (BCM) indicating the engine coolant temperature. The IPC displays the engine coolant temperature based on a GMLAN message from the body control module (BCM) indicating the engine coolant temperature. Refer to Data Link Communications Description and Operation and Body Control System Description and Operation . The engine coolant temperature gage defaults to 38°C (100°F) if:

The instrument panel cluster (IPC) displays the fuel level as determined by the powertrain control module (PCM) or the engine control module (ECM). The PCM/ECM sends a GMLAN message to the body control module (BCM) indicating the fuel tank level remaining. The IPC displays the fuel level based on a GMLAN message from the BCMindicating the fuel tank level remaining. Refer to Data Link Communications Description and Operation and to Body Control System Description and Operation . The fuel gage defaults to E (empty) if:

When the fuel level is less than 14 percent, the low fuel indicator/message illuminates.

The vehicle odometer is calculated and stored electronically in the body control module (BCM). The BCM calculates and stores the mileage based on the vehicle speed GMLAN message from the powertrain control module (PCM) or the engine control module (ECM). The instrument panel cluster (IPC) displays the season odometer information sent from the BCM over GMLAN. Refer to Data Link Communications Description and Operation and Body Control System Description and Operation . The odometer will display 'error' if an internal IPC memory failure is detected or if there is a GMLAN communication fault between the PCM/ECM and the BCM.

The driver information center (DIC) in the radio displays Trip Odometer A or Trip Odometer B information sent from the BCM over GMLAN serial data circuit. Press the INFO button until Trip A or Trip B is displayed. The trip Odometer displays the current distance traveled since the last reset for each Trip Odometer (A or B) in either miles or kilometers. Both odometers can be used at the same time. Each trip odometer can be reset to zero separately by pressing and holding the ENTER button for a few seconds while the desired trip odometer is displayed. The Trip A or Trip B Odometer will display "- - -.- -" if there is a GMLAN communication fault between the PCM/ECM and BCM.

The instrument panel cluster (IPC) displays the selected gear position as determined by the powertrain control module (PCM) or the engine control module (ECM). The PCM/ECM sends a GMLAN message to the body control module (BCM) indicating the gear position. The IPC displays the gear position based on a GMLAN message from the BCM indicating the selected gear position. Refer to Data Link Communications Description and Operation and Body Control System Description and Operation . The PRNDL display blanks if:

The instrument panel cluster (IPC) displays the vehicle speed based on the information from the vehicle speed sensor. The IPC receives a GMLAN message from the body control module (BCM) indicating the vehicle speed. The IPC calculates and displays the vehicle speed based on the GMLAN message from the BCM indicating the wheel reference speed. Refer to Data Link Communications Description and Operation and to Body Control System Description and Operation . The speedometer defaults to 0 km/h (0 mph) if :

The instrument panel cluster (IPC) displays the engine speed as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC displays the engine speed based on a GMLAN message from the body control module (BCM) indicating the engine speed. Refer to Data Link Communications Description and Operation and Body Control System Description and Operation . The tachometer will default to 0 RPM if: