Certain instrument panel cluster (IPC) features are tested when the ignition is turned on in order to verify that 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 radio sends current time to the IPC via class 2. The IPC receives a class 2 message from the radio indicating the time. The IPC analog clock, if equipped, zeroes itself to 12:00 during key up and then resets to the current time via the class 2 message received from the radio.

The ECM sends the coolant temperature to the BCM via class 2. The IPC displays the engine coolant temperature as determined by the BCM. The IPC receives a class 2 message from the BCM indicating the engine coolant temperature. The engine coolant temperature gage, if equipped, defaults to 75°C (160°F) or below if:

Refer to Cooling System Description and Operation in Engine Cooling for more information.

The ECM sends fuel level percent to the IPC via class 2. The IPC displays the fuel level as determined by the ECM. The IPC receives a class 2 message from the ECM indicating the fuel level percent. The fuel gage defaults to E (empty) if:

When the fuel level is less than 4%, the low fuel indicator illuminates. Refer to Evaporative Emission Control System Description in Engine Controls for more information.

The IPC displays the vehicle mileage and trip mileage as determined by the ECM. The IPC calculates the vehicle mileage based on the speed pulses from the VSS signal and calculating the mileage for odometer displays. The odometer will display 'error' if an internal IPC memory failure is detected and DTC B1009 is set.

The IPC displays the vehicle speed based on the information from the ECM. The ECM sends a 4000 pulse per mile signal to the cluster discretely. The IPC calculates the vehicle speed using the time difference between consecutive pulses. The speedometer will default to zero if the time duration since the last speed pulse is greater than or equal to one second.

The IPC receives a discrete input from the ECM indicating vehicle speed. Each engine revolution is represents two input pulses to the ECM. The instantaneous engine speed is calculated by the ECM using the time difference between the two input pulses. The tachometer will default to 0 rpm if: