Vehicle Speed Sensor (VSS)
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Mitsubishi Outlander, 2003 Mitsubishi Montero Sport, 2003 Mitsubishi Montero, 2003 Mitsubishi Lancer, and 2003 Mitsubishi Galant. However, it is still accessible from the selected car via links, so may be relevant.
Remove VSS from rear of transmission or top of transaxle. Connect 3-10 k/ohm resistor as shown in Fig 1. Connect voltmeter between terminals No. 2 and 3. Spin shaft of VSS and check for voltage pulsations. There should be about 4 voltage pulsations per revolution. If there are not 4 pulsations per revolution, replace VSS.