SW1 L4-1.9L SOHC VIN 8 (1996)
Speedometer Head: Description and Operation
The speedometer receives vehicle speed information from the powertrain control module (PCM). The vehicle speed signal is passed through an RC
filter to the input of the speedometer/odometer drive integrated circuit (IC), located in the instrument cluster. The high-to-low edge of the square wave
input triggers the IC to produce a well defined pulse of current to the moving coil inside the speedometer gauge. The IC also counts the input transitions
and uses this information to drive the stepper motor for both odometers. The vehicle completes one mile for every 4983 pulses received from the PCM.
