I obtained a new to me 2006 Cobalt ss. It's mechanically in tune, but has a flaw of the speedometer not working. It stays at 0. In turn this makes my odometer not count miles, and possibly has the cruise control think I'm setting it to 0 MPH, too.

Electrical problems are out of my knowledge so I took it to a place they matched the wiring and how it's supposed to be to GMs diagram, and still have no dice. They Ohmed each cord and said all have connectivity.

I have 2 ideas I still can do, Double check my fuses, and secondly where can I find the cable that goes to the transmission? I want to check that.

My friend thought it was my cluster, I don't think that's the problem. The shop said the whole ECM has to be replaced which I don't think is right at all. Any suggestions would be greatly appreciated.