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Home >> Saturn >> 1999 >> SL1 L4-1.9L SOHC VIN 8 >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Vehicle Speed Sensor >> Description and Operation
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Vehicle Speed Sensor: Description and Operation

VEHICLE SPEED SENSOR
The PCM provides vehicle speed to the instrument cluster for the speedometer by way of the VSS. The vehicle speed sensor (VSS) is a variable reluctance pulse generator that senses the transaxle output. It operates between 0-161 km/h (0-120 mph).

PULSE OUTPUT
The PCM supplies an output to the instrument cluster (speedometer/odometer). This signal is 5000 pulses/mile, representing the divided down vehicle speed. It is a square wave signal from 0 to 12 volts. The correct output to the speedometer depends on the PCM being programmed with the correct tire size. Refer to Vehicle ID table using a Scan tool to be sure tire size option matches the tire size on the vehicle.

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