E 250 V8-4.6L SOHC VIN W (2004)
Speedometer Head: Description and Operation
Speedometer/Odometer
The instrument cluster receives vehicle speed information from the powertrain control module (PCM) via the standard corporate protocol (SCP)
network. On vehicles equipped with gasoline engines, the PCM receives its signal from the output shaft speed sensor (OSS). On vehicles equipped with
diesel engines, the PCM receives its signal from the vehicle speed sensor (VSS).
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 two seconds, the odometer display will show dashes.
