Principles of Operation: Speedometer/Odometer

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, and 2005 Ford E450 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

The instrument cluster receives vehicle speed information from the powertrain control module (PCM) over the communication 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 3 functions. First, pressing the SELECT/RESET button toggles 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 2 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 ignition switch in the OFF position, then turning the ignition switch 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 shows dashes.