Message Center Displays

Compass Display

The compass is displayed as a 1 or 2 character display and as a virtual compass ball (mid-level and high-level IPC only). The IPC receives the compass direction from the APIM over the HS-CAN3.

Digital Speedometer

The IPC provides a digital speedometer display to indicate vehicle speed in a digital format. The IPC uses the internally commanded speedometer speed (based on the vehicle speed message sent from the PCM) to provide an accurate digital speedometer display.

DTE/Average Fuel Economy (AFE)

The DTE is calculated in the IPC using the Running Average Fuel Economy (RAFE), which is the fuel economy over the last 480 km (300 miles), and the fuel level input from the fuel sender(s) to determine how many kilometers (miles) the vehicle can be driven based on the remaining fuel in the tank. The DTE can vary in the short term by up to 80 km (50 miles), but is usually within 16 km (10 miles). Even if the fuel economy is relatively constant, the DTE can be off over a 80 km (50 mile) range by -24% to +38%. The DTE display and the fuel gauge both use the fuel level input from the fuel tank to provide their respective functions. If the fuel gauge doesn't function correctly, both the fuel gauge and the DTE display are affected.

The IPC defaults to a preset baseline mpg when the battery is initially connected and changes based on driving habits and conditions.

NOTE: The actual DTE can be higher or lower than the DTE displayed in the message center due to changes in driving conditions. It is important to understand how the DTE is calculated and the factors that impact the DTE display when determining how to address any DTE concerns.

Since the DTE is calculated and averaged over a longer period of time (480 km [300 miles]), varying driving conditions can have a significant impact on the current or short term DTE as opposed to the displayed DTE. This difference often leads to customer complaints of incorrect or invalid DTE. The following list provides some (not all) of the driving conditions that may lead to an incorrect or fluctuating DTE concern:

Changing between towing/not towing
Changing driving between city and highway
Allowing the vehicle to idle for long periods of time
Using the remote start feature frequently to allow the vehicle to warm up, particularly when parked on a grade
Parking or driving on grades
Inconsistent use of gasoline or E85 fuels
Over-fueling or not filling the tank completely (partial refueling)

The IPC uses the following network messages to control the DTE/Average Fuel Economy (AFE).

Fuel alcohol percent
Fuel flow volume display
Odometer count
Transport mode

The IPC receives all messages from the GWM over the HS-CAN3. The GWM receives the transport mode message from the BCM over the HS-CAN1 and the fuel alcohol percent, fuel flow volume display and the odometer count messages from the PCM over the HS-CAN1.

Odometer

The IPC receives the odometer count message from the GWM over the HS-CAN3. The GWM receives the odometer count from the PCM over the HS-CAN1. The IPC monitors the odometer count input from the GWM and commands the odometer with a digital display in the message center.

Outside Air Temperature

The Ambient Air Temperature (AAT) sensor is hardwired to the PCM through separate input and return circuits. The PCM provides a reference voltage to the Ambient Air Temperature (AAT) sensor and monitors the change in voltage resulting from changes in resistance as determined by outside air temperature.

The PCM provides the ambient air temperature data to the GWM over the HS-CAN1. The GWM sends the ambient air temperature data message to the HVAC module over the MS-CAN. The HVAC module sends the filtered ambient air temperature data to the IPC over the HS-CAN3.

The HVAC module is programmed to update the messaged outside temperature data at different rates depending on several criteria (current engine temperature, engine off time and vehicle speed) to prevent false temperature displays due to a condition known as heat soaking. Heat soaking is where the outside air temperature is hotter in the location of the Ambient Air Temperature (AAT) sensor than the actual outside air temperature.

TPMS

The IPC provides a message center display showing each tire on a vehicle image to indicate specific tire pressures.

The IPC receives the tire pressure system status and tire pressure data messages from the GWM over the HS-CAN3. The GWM receives the tire pressure system status and tire pressure data messages from the BCM over the HS-CAN1.