pepsi2451

So I wanted to put a mpguino in my truck and decided to try it first on a breadboard. At first all seemed to work fine except it said I was going 60 when I was going 50. At some point when I was trying to dial in the PPM I lost VSS signal. I don't know what happened, something may have shorted out although I don't see how. Now I can't seem to get any signal from the VSS wire at the ECM. My speedometer still works, the truck still seems to drive the same and it hasn't given me an error code yet.

Since my speedometer is still working I'm assuming its cable driven. Do I really need a VSS? If I did decide to replace it is it the same $100+ part as the trucks with electronic speedometers, that mounts to the transmission? Or is it something in my intrument panel that sends the VSS signal to the ECM?

Any help would be greatly appreciated.

pepsi2451

I did some more research and it looks like the VSS signal probably comes from a reed switch on the mechanical speedometer. I will try to stop by radio shack tomorrow and see if I can get a switch. Hopefully I will have time to try replacing it this weekend.