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:

Refer to Indicator/Warning Message Description and Operation .

The instrument panel cluster (IPC) displays the engine coolant temperature on the analog engine coolant temperature (ECT) gage as determined by the powertrain control module (PCM). The PCM monitors the signal circuit of the ECT sensor. The IPC receives a class 2 message from the PCM indicating the engine coolant temperature. The IPC illuminates the check gages indicator when a high engine coolant temperature condition exists. The ECT gage defaults to 75°C (160°F) or below when one of the following conditions occur:

For additional information on the engine cooling system, refer to Cooling System Description and Operation .

The instrument panel cluster (IPC) displays the engine oil pressure on the analog engine oil pressure (EOP) gage as determined by the powertrain control module (PCM). The PCM monitors the signal circuit of the EOP sensor. When the EOP sensor resistance is high, the engine oil pressure is high. When the EOP sensor resistance is low, the engine oil pressure is low. The IPC receives a class 2 message from the PCM indicating the engine oil pressure. The IPC illuminates the check gages indicator when a low oil pressure condition exists. The EOP gage defaults to 0 kPa (0 psi) when the following condition occurs:

The instrument panel cluster (IPC) displays the fuel level on the analog fuel gage as determined by the powertrain control module (PCM). The PCM monitors the signal circuit of the fuel level sensor. When the fuel level sensor resistance is high, the fuel gage indicates full. When the fuel level sensor resistance is low, the fuel gage indicates empty. The IPC receives a class 2 message from the PCM indicating the filtered fuel level percent. The PCM uses 2 filters for the fuel level percent. The slow filter is used during normal operation. The fast filter is used when the engine is just started or when the vehicle is in Park or Neutral. The fast filter allows the fuel gage to reach the current fuel level quickly. The fuel gage defaults to empty when the following conditions occur:

Reviewing the fuel system description will further explain how the system functions. Refer to the following procedures:

The instrument panel cluster (IPC) displays the season odometer, the trip odometer A, and the trip odometer B. Momentarily press the trip/reset switch on the IPC in order to toggle the odometer display between the season odometer, the trip odometer A, and the trip odometer B. Press the trip/reset switch for greater than 2 seconds, while the trip odometer A or the trip odometer B is displayed, in order to reset the trip odometer. The IPC calculates the mileage based on the vehicle speed class 2 message from the powertrain control module (PCM). The IPC updates the values of both trip odometer A and trip odometer B regardless of the trip odometer being displayed. The odometer will display Error if an internal IPC memory failure is detected.

The instrument panel cluster (IPC) displays the selected gear position as determined by the powertrain control module (PCM). The IPC receives a class 2 message indicating the gear position. The PRNDL display blanks when the following conditions occur:

The instrument panel cluster (IPC) displays the vehicle speed based on the information from the powertrain control module (PCM). The PCM calculates the vehicle speed from the vehicle speed sensor (VSS) circuit. The IPC receives a class 2 message from the PCM indicating the vehicle speed. The PCM also calculates the vehicle speed based on the wheel reference vehicle speed class 2 message from the electronic brake control module (EBCM). The PCM uses the vehicle speed information from the EBCM as a backup. The IPC displays the vehicle speed information from the EBCM when the PCM detects a malfunction in the vehicle speed sensor circuit.

The speedometer defaults to 0 km/h (0 mph) if the IPC detects a loss of class 2 communications with both the PCM and the EBCM.

The instrument panel cluster (IPC) displays the system voltage as detected at the ignition 1 input of the IPC. When the engine is ON, the gage should be between 10-16 volts.