aftermarket curise not working,03 cav

I have a 2003 cavalier that a dealer dropped off.  They had cruise control install, and it worked fine, I guess.  It doesn’t work now and I tested all wires, everything works except the GREEN / WHITE wire at the PCM.  I tried to test this wire several way…driving car back/forth, and jacked it up and spun the front wheel by hand.  No readings either way.  The speedometer works fine.  What controls this VSS wire?  Could their be a bad sensor?  Could I be testing wrong?   (Yes i'm testing w/ meter set to AC)

 

Thanks for any help, Chris

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                                                   ***Sorry about that****

I have a 2003 cavalier that a dealer dropped off. They had cruise control install, and it worked fine, I guess. It doesn’t work now and I tested all wires, everything works except the GREEN / WHITE wire at the PCM. I tried to test this wire several way…driving car back/forth, and jacked it up and spun the front wheel by hand. No readings either way. The speedometer works fine. What controls this VSS wire? Could their be a bad sensor? Could I be testing wrong? (Yes i'm testing w/ meter set to AC) Thanks for any help, Chris

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Owner/ Custom Compact Performance

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The GREEN / WHITE wire is the VSS wire from the PCM. There are multiple ones, but the correct one is in cavity 34. There could be any number of problems with it. You said that you have checked the wiring. What kind of cruise is it. If you don't know then you may be testing the wires incorrectly. Some cruises need to see a ground on the switched side of the brake to work. They will lose this ground reference when the brakes are applied and cut the cruise off. If the throttle still hooked up? Is the cruise a vacuum unit? Need more info.

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sparky

The wire is in cavity 34, although every GREEN / WHITE wire there has electric tape on it.  Poke and hope I guess?  The unit was working for years.  Then one day it stoped.  The unit is a SCS/Frigette.  A simple search and I found their web site. They have install instructions on there.  I went through every wire and all truble shooting, this is the only wire I cant get to test right, well at all.  The model is a 202-3215, electric servo, not vacuum.  The unit need a 12v input at the brake which is good, all other conections are good.   This VSS wire seams to be my trouble?  Also it looks as though the throtle is hooked up.

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Owner/ Custom Compact Performance

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The VSS wire can be tested using a digital volt meter set to AC voltage. I seriously doubt that it is your problem. Check the wire for continuity from the ECM to the cruise. Also recheck your brake wire. As I said you DO NOT check it for 12 volts when you apply the brake. You MUST check it for less than 10 ohms resistance to ground with the ignition off. If you have burnt out brake light bulb, this is enough to throw off the resistance and not allow the cruise to work. Check it. I have seen some of these cars have a problem in the brake circuit, but the brake lights still work. If all checks, then it is probabaly the cruise itself. I am not familiar with those units and their reliability.

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sparky

Ok I checked the wire for continuity from the ECM to the cruise, it was  .5 ohms.   That should be fine?  Also this unit needs Two brake inputs, one constent 12v the other 12v during braking.  They both test fine.  I tested the resistence w/ the key off on the brake wires, the switched one only reads, .7ohms.  Here is the install sheet if your instered. https://www.scsfrigette.com/html/TechSupport/PDFTSupport/601-7563.pdf

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Owner/ Custom Compact Performance

Treo,Cadence,ARC Audio
Critical Mass/Icon TV
Panasonic,Compustar,Scosche