speedometer problem

[yuliank]

My speedo not working on a Suburban. I put in new VSS, swapped speedo from a different sub, no difference. Could my cranc position sensor be on the way of the problem? Hard and irregular shifting 1st to 2nd gear. Shifts at different RPM and kicks. Also cruise sontrol dont work. I think its tied together. ABS light comes on after driving for a few seconds. Meybe ABS sensor is tripping something. Speedo don't move at all. Any one had this issue before?

 

[THEFERMANATOR]

Sounds like a VSSB problem. The ABS, speedo, and PCM all receive the vehicle speed sensor signal from the vehicle speeed sensor buffer(little white box located behind the glove box underneath the PCM). The VSS connects to it on the 6.5's and it sends out the signal to everything else. The cruise not working means that the ECM isn't getting a speed signal as well as the 1-2 shift as it will default to 2nd gear when there is a problem and it goes into limp mode. Also the ABS receives it's signal from it and would trigger the light when it sees a speed from the front wheels and not from teh VSSB. It could be bad wiring, or a bad VSS, or simply the VSSB could be bad. Need to get in there with an ohm meter and start checking your wiring. Also you can check for VSS output with a volt meter to make sure it is working.

EDIT: I see from your other post your having electrical issues. I would get the wiring fixed first as that is most likely your problem.

 

[Turbine Doc]

X2 you need to be looking into gnds, these rigs have multiple paths to gnd & segregated gnd loops that are somewhat independent of each other, check the TRL http://www.thetruckstop.us/forum/forumdisplay.php?218-6.2-and-6.5-Technical-Reference-Library for some good info on gnds and other 6.2/6.5 info.