J2000/Sunbird V6-191 3.1L VIN T MFI (1994)
Vehicle Speed Sensor: Description and Operation
The Vehicle Speed Sensor is a gear-driven Permanent Magnet Generator housed in the vehicle's transaxle. This sensor generates a sine wave output with
a frequency proportional to vehicle speed. The Engine Control Module (ECM) converts this signal to an output that is switched to ground at a frequency
of 4000 pulses per mile at the DK GRN (389) wire output. This output is pulled up to 5 volts or greater by the components that use this speed signal as
an input.
