Econoline E550 V8-7.3L DSL Turbo VIN F (2002)
Vehicle Speed Sensor: Description and Operation
4R100
4R100 Transmission
NOTE: Vehicle Speed Sensor (VSS) only applies to 7.3L Diesel engines only.
Vehicle Speed Sensor (VSS)-7.3L Diesel Only
The vehicle speed sensor (VSS)(model-dependent) is a variable reluctance sensor that sends an A/C frequency signal to the powertrain control module
(PCM). The VSS sensor signal is used by the PCM to calculate vehicle speed in mph and determine shift scheduling and electronic pressure control.
For diesel applications the VSS is used for output speed sensing, supplying the PCM with transmission output speed. The PCM then sends the TCC pulse
width modulated signals to smoothly engage the torque converter clutch.
