Does anyone have an Idea where the issue may be, Speedometer acts like a broken speedometer cable, it bounces untill you reach about 15 mph then stays still - I Have changed the speed sensor on the tranny , but it does the same thing , just bounces

Randomly it will work perfectly for about a second or so ,

The odometer works fine, Cruise control works good ,

your speedometer itself is bad. Your cluster is electronic, and the speedo is basically an ohm meter that changes the needle position as the signal resistance from the vss changes.

I Was thinking that as well, This morning I Changed the guage cluster out , Same thing , Milage works, speedometer doesnt ,, any other thoughts ?

could it be the computer?

oh , and the second cluster i installed, didnt jump at all,

my next guess would be the harness at the cluster has a bad wire or connector, or has some corrsion at the vss connector, and it only acts up at low speed because that is the lowest current position.

ok , ill check all that out , basically the faster you go the less it jumps untill it stops working :(

BTW Thanks for helping :) ill post what i find when i test

good luck, hope you find the problem.

Correct me if I am wrong, but isn't there a speed sensor on the tranny that give the gauge the pulses to show the speed?

By GM schematics, the VSS feeds to the PCM which feeds to the cluster to run the ODO motor and the Speedometer coils.