Cutlass L4-138 2.3L VIN A FI HP (1990)
Vehicle Speed Sensor: Description and Operation
Vehicle Speed Sensor (VSS)
The Vehicle Speed Sensor provides information to the ECM for control of idle speed and transmission converter clutch engagement as well as
controlling canister purge of the fuel evaporative emission system. This signal is generated by an optical sensor in the speedometer head or a Permanent
Magnet generator located in the transmission.
