Hesitating whilst driving.

[Daytime172]

Was wondering if anyone has had a problem with there car as Im having a misfire/judder whilst driving along in low revs, I plugged my diagnostics tool in and was showing up vehicle speed sensor 'A' - P0500. Any help would mean a lot thank you

 

[Greeny.]

I had a similar thing, followed by it constantly running on three, ended up being a blocked injector.

 

[Daytime172]

I replaced all the injectors,coil pack new plugs and leads ,but what is the VSS anyway as that's what it was coming up with on the diagnostics tool?