1. Disconnect the electrical connector from the VSS.
2. Connect a voltmeter between the VSS signal terminal and ground.
3. Start the engine and turn on the ignition.
4. The voltmeter should read a fluctuating voltage between 0 and 5 volts.
5. If the voltmeter does not read a fluctuating voltage, the VSS is faulty and needs to be replaced.
Here are some additional tips for testing the VSS:
* Make sure that the speedometer cable is properly connected to the VSS.
* Check the wiring between the VSS and the ECU for any damage or loose connections.
* If the VSS is still not working properly, you may need to have the ECU tested.