E 450 V10-6.8L (2008)
Speedometer Head: Description and Operation
Speedometer/Odometer
The instrument cluster (I/C) receives vehicle speed information from the powertrain control module (PCM) over the high speed controller area network
(HS-CAN) communication bus. The instrument cluster monitors the vehicle speed input and commands the speedometer with a corresponding movement
of the pointer.
The SELECT/RESET button has three functions. First, pressing the SELECT/RESET button will toggle between the odometer and trip odometer
settings. When the trip odometer is displayed, pressing and holding the SELECT/RESET button will reset the trip odometer. There are two trip
odometers available: A and B. Pressing the SELECT/RESET button while in trip odometer will toggle between trip odometer A and trip odometer B.
Lastly, the instrument cluster self-test is entered by pressing and holding the SELECT/RESET button down with the key in the OFF position, then
turning the key to RUN.
The instrument cluster receives odometer rolling count status from the PCM and stores the mileage in non-volatile memory (NVM). When the instrument
cluster fails to receive the odometer rolling count status for more than 5 seconds, the odometer display will show dashes
