F 350 4WD Pickup V8-351 5.8L VIN H EFI (1997)
Speedometer Module: Description and Operation
Automatic Transmission
Programmable Speedometer/Odometer Module (PSOM).
Purpose
The Programmable Speedometer/Odometer Module (PSOM) is Used as an input in determining shift scheduling and electronic pressure control.
Operation
The PSOM receives input from the rear brake anti-lock sensor, which is mounted in the rear axle differential housing. The PSOM processes this
input signal information and relays it to the powertrain control module and the speed control module. This signal tells the powertrain control
module the vehicle speed in miles per hour.
