If tests show that a sensor is working fine and is not handling any driveability problem or trouble code, check the wiring harnesses and connectors between the said sensor and PCM for any shorts or opens. If there is no problem identified, it is also wise to have the car checked by a dealer's service section or any automobile repair center. The VSS is a pickup coil, variable-reluctance type, attached to the transaxle case; this unit produces a sine-wave AC voltage, with the frequency being a direct function of vehicle speed. The PCM uses the signal from the sensor for different operations of the engine and the transmission and the signal from VSS serves as a power source for the speedometer on the instrument cluster. These are due to varied reasons including multiple driveability and transmission problems that emanate from a malfunctioning VSS, depiction of sensor faults and trouble codes by the Electronic Engine Control system. To check the VSS, remove its connector and switched on the ignition without starting the car, then check the voltage between the sensor's wire connector and ground, should be about of 1 to 5 volts in one of the wires of the sensor. If this is the case, unbolt the VSS and attach an AC Volts meter to it to read for voltage pulsing during the spinning of the sensor drive gear; absence of voltage pulsing, the sensors should be replaced. For replacement, safely lift the vehicle on jack stands, then loosen the negative cable from the VSS and unbolt and then remove the hold down bolt and clamp and the take out the VSS from transaxle. Take out the O-ring on the sensor and check it for damage, if installing a new sensor use a new O-ring. In the same order as removal, reinstallation starts with the uppermost processed layer.