Grand AM L4-138 2.3L VIN A MFI (1992)
Speedometer Head: Description and Operation
Base Cluster
The Speedometer pointer is moved by the magnetic field of two coils. These coils are driven by a solid state unit.
The Vehicle Speed Sensor located in the transaxle generates an AC voltage that is sent to the Engine Control Module (ECM). The ECM processors
this voltage into a square wave. The pulses generated are sent to the Speedometer at 4000 pulses per mile.
