Ok, I get it. You have an automatic. The vss signal the guino is looking for is like 0 to 12 volts, and there should be one in your dashboard still feeding the ECU (yellow green). There is also a vss on the automatic transmission that is probably in the millivolt range that only serves the transmission, at least according to the last post in this thread:
TeamSwift • View topic - VSS Circuit Problem!
I think the ECU speed signal will set your speed right.