Vehicle Speed Sensor (VSS)
- Vehicles have one VSS located in vehicle speedometer and one mounted on left rear of transmission. Transmission mounted VSS sends signal to speedometer VSS, which controls needle movement and sends signal to ECM and cruise control.
- For testing speedometer VSS, remove speedometer from meter assembly. Using DVOM, measure resistance value between terminals 4P and GND. See Fig 1 . Resistance should be 13,500-16,000 ohms. If resistance is not as specified, replace speedometer assembly.
- For testing transmission mounted VSS, remove VSS from transmission by rotating sensor body. Connect jumper wire between VSS connector terminal No. 1 and positive battery terminal. See Fig 1
.WARNING: DO NOT connect battery voltage to VSS connector terminal No. 3; VSS damage will result.
- Connect jumper wire between VSS connector terminal No. 2 and negative battery terminal. Connect 1.3k-5k ohm resistor (1/4 watt or more) between VSS connector terminals No. 1 and 3.
- Using a DVOM, measure voltage across resistor while rotating sensor shaft slowly. With one rotation of sensor shaft, voltage should fluctuate 4 times. Ensure voltage fluctuates between 10-14 volts and 2 volts or less. If sensor voltage is outside specification, replace VSS.