VSS question
Thread Starter
Staging Lane
Joined: Dec 2016
Posts: 62
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VSS question I hope I posted in the correct spot. I have a 2002 Astro van with a 2001 LS1. The engine is run from a "painless wiring" harness and the chassis is run from the original ECM. The painless harness has no provisions for gauges. It does have the green wire out of the ECM on pin 50 for the VSS out, but now that the harness is in and wrapped I can not easily trace it to see where it goes. I have contacted painless and they are reluctant to tell me for some reason where that wire is going. My question is can I splice the wires from the old and new VSS sensor together and get my speedometer to run without damage to anything. Or does anyone know what that green VSS out wire feeds besides the speedometer? It apparently does something on mine as there are no open ended wires.
TECH Addict
Joined: Aug 2005
Posts: 2,305
Likes: 126
From: Monroe,NY
you need to connect the vss from the tranny so the pcm knows your speed. pin 50 goes to your speedometer. On my 1992 chevy pickup i tapped into the vss from the tranny to my 1999 5.3 pcm while it is still connected to the 1992 ecm and everything worked fine as before the swap. The one problem with mine was the speedometer always read higher than actual speed(it was like this before swap also). So i used the output pin 50 to my speedometer so i could adjust through the 5.3 pcm so my speedometer would read correctly.
