20V Faulty Speed Sensor???

[aarong420]

I've been getting the engine light coming on in my corolla, but when i switch off, the code goes away. So instead of swithcing off. When the engine check light came on, i just connected TE1 and E1 while the car was running, and got the 4-2 code, which is the vehicle speed sensor.
What I need to know is, my speedometer isnt connected, because the cluster is cable driven. Is this the reason the code is coming up?. or is it because it is a faulty speed sensor.?
I would hate to replace the sensor if the reason its coming up is because its not connected to the speedo??