Hey guys and gals, I have a 1999 jimmy/blazer and the other day while driving home the transmission stopped shifting and the speedometer stopped working as well, it now only stays in second, reverse still works. The check engine light came one and I scanned it and got a code: p0500, a vss malfunction. I changed the vss (new from gm) and nothing has changed. I checked the voltage across the vss connector and it was 4.69v (dc) which is between the normal 4-5.1v rating, next I tested it at the vcm harness (blue connector) at the third and forth pin from the right and got 1462 ohms which is between the 926-2354 ohms that is considered normal. I now have no idea what else to trouble shoot. Am I required to reset/flash the vcm after I have installed this new vss? I was told it was not needed. If anyone can pitch in there thoughts or past experiences it would be extremely appreciated.
Thank you.

 

I'm assuming it is a two wheel drive? When you had the speed sensor out, did you happen to check inside the hole and make sure the reluctor ring was intact and free of magnetized debris?

This may seem elementary, but check for blown fuses with a test light. Thoroughly clean all the ground points. I was going to ask if you checked the wires for continuity to the computer but if I'm reading you right you measured the resistance of the new part from the connecter at that end so the circuit should be complete. Barring a physical problem with the reluctor ring on the output shaft, next step would be to try a used computer. If you can lay your hands on one.