I got an 89 iroc with a 350 tpi. I am getting a code 24 which is a vss problem. I have a cable speedo and the vss is on the back of the speedo cluster. The speedo works fine. the torque converter is not locking up at all when driving and when you let of the gas to coast, the rpms go straight back to idle. I have a scanner that can view data stream and when I drive it down the road, the vss is showing 0 mph. The car idles rough but doesnt stall and the engine still runs good. Haynes or chiltons doesnt show anything about how to diagnose this style vss, just the one on the trans. Chiltons show a wiring diagram for the vss on the cluster but doesnt do me much good. Could the vss itself be bad or could it be something else like the computer? Is there a way to test this to see which one it could be? Thanks.

 

I have the same exact symptoms with the TC lock up. I haven't checked my codes, but my "check engine" light does come on sometimes. I'd like to hear opinions on this.