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 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 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.