Vehicle speed sensor reads the actual speed of the vehicle, which is shown to the driver via speedometer. This video provides some symptoms when the speedo sensor starts to fail.
Commonly asked question:
Why do my speedometer fluctuates?
Where is wheel speed sensor located?
How to replace a wheel speed sensor?
What is vehicle speed sensor?
How do speed sensor work?
Bad vehicle speed sensor symptoms.
Signs of bad vehicle speed sensor.
Speedometer not working.
Can a bad wheel speed sensor cause acceleration problems?
Bad transmission speed sensor signs.
Diagnose a transmission speed sensor.
How to diagnose a bad wheel speed sensor?
Why do my speedometer keeps failing?