Vats or not Vats?
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Joined: Jul 1999
Posts: 120
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From: Denton, TX
Car: 1992 RS
Engine: 305
Transmission: A/T
Vats or not Vats?
So every once and a while for the last few days my car wouldn't attempt to crank. A few minutes later it would. I just assumed it was the starter or solenoid since it was old and a cheap lifetime warranty one. I replaced the starter and all the old original battery cables and even had the alternator and battery tested for good measure. Everything seemed great and it started with every test after I finished yesterday. I go out to start it this morning and it's back. No crank.
I noticed after the first failed crank attempt if I pull the key out and put it back in the "security" light would come on solid and stay on with every attempt unless I waited a few minutes. I tried my 2nd original key that has low wear and there was no difference. Does this sound like a simple Vats issue that I can bypass? From what I've read there's no other reason the "security" light would come/stay on unless it was Vats. I guess I just expected it to be on on the first attempt as well. Maybe that's just the way it works. Thanks guys.
I noticed after the first failed crank attempt if I pull the key out and put it back in the "security" light would come on solid and stay on with every attempt unless I waited a few minutes. I tried my 2nd original key that has low wear and there was no difference. Does this sound like a simple Vats issue that I can bypass? From what I've read there's no other reason the "security" light would come/stay on unless it was Vats. I guess I just expected it to be on on the first attempt as well. Maybe that's just the way it works. Thanks guys. Joined: Dec 2004
Posts: 16,771
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Joined: Aug 2009
Posts: 1,821
Likes: 40
From: Central California
Car: 92 Camaro RS
Engine: LO3
Transmission: T5
Axle/Gears: stock
Re: Vats or not Vats?
If you want to do the resistor thing, here's one of several sources that makes it easy to get the right ones
Supreme Member
Joined: Apr 2006
Posts: 4,482
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From: Northern, CA
Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: Vats or not Vats?
Jump the starter enable relay like this.
The relay is removed and you use the two outside slots.
Its in the drivers side kick panel by your left foot.
This is a random photo I found.
Use a heavy gauge wire with spade connectors as shown then rap it with electrical tape to protect it and keep the jumper in.
Quite a lot of voltage going through that wire when you crank the car so be careful.
That will keep the VATS System from disabling the starter.
If its VATS the car will now crank every time but you will not get fuel.
Once you install the resister it should now start.
The relay is removed and you use the two outside slots.
Its in the drivers side kick panel by your left foot.
This is a random photo I found.
Use a heavy gauge wire with spade connectors as shown then rap it with electrical tape to protect it and keep the jumper in.
Quite a lot of voltage going through that wire when you crank the car so be careful.
That will keep the VATS System from disabling the starter.
If its VATS the car will now crank every time but you will not get fuel.
Once you install the resister it should now start.
Supreme Member
Joined: Apr 2006
Posts: 4,482
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From: Northern, CA
Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: Vats or not Vats?
Here's how you test your key for resistance. Only touch the resister with the tester set on ohms/resistance.
You should be able to take that "value" to Radio Shack and find the resistor or resistors you will need.

Here's where I put my resister.

If you don't solder you can get very small "butt" connectors at Radio Shack also.
There just tiny little metal tubes. No plastic on them like this. = = https://www.radioshack.com/products/...utt-connectors
You should be able to take that "value" to Radio Shack and find the resistor or resistors you will need.

Here's where I put my resister.

If you don't solder you can get very small "butt" connectors at Radio Shack also.
There just tiny little metal tubes. No plastic on them like this. = = https://www.radioshack.com/products/...utt-connectors
Last edited by Ron U.S.M.C.; Jun 14, 2017 at 03:44 AM.
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Joined: Dec 2004
Posts: 16,771
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From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Vats or not Vats?
If you want the vats gone for good send me a pm. I can program a prom to eliminate it completely.like Ron pointed out the starter enable relay would need to be bypassed.
Thread Starter
Member
Joined: Jul 1999
Posts: 120
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From: Denton, TX
Car: 1992 RS
Engine: 305
Transmission: A/T
Re: Vats or not Vats?
Would the prom replace my ADS Superchip from 1990 something? What's the function of leaving the starter enable relay bypassed once vats is confirmed as the fault? My understanding is that it's just a troubleshooting method to confirm vats is cutting the starter and fuel.
Joined: Dec 2004
Posts: 16,771
Likes: 1,001
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Vats or not Vats?
The vats also controls the enable relay, a new prom would replays the super chip.
Thread Starter
Member
Joined: Jul 1999
Posts: 120
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From: Denton, TX
Car: 1992 RS
Engine: 305
Transmission: A/T
Re: Vats or not Vats?
Oh so the VATS bypass by prom would need the starter enable relay manually bypassed as well?...because it needs to be controlled by VATS and VATS is no longer "there" so it would default to disabled? Why would no manual "fuel relay" (or however VATS cuts fuel) bypass be necessary in that case as well?
So if you bypass by resistor everything stays where it is, you're just always telling VATS the right key is in and there would be no reason to bypass the starter enable relay correct? What would be the benefit of prom/starter relay bypass over resistor only?
So if you bypass by resistor everything stays where it is, you're just always telling VATS the right key is in and there would be no reason to bypass the starter enable relay correct? What would be the benefit of prom/starter relay bypass over resistor only?
Joined: Dec 2004
Posts: 16,771
Likes: 1,001
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Vats or not Vats?
The resistor just bypasses the lock cylinder reader. The vats kills fuel injector pulse. A prom with vats programmed out the ecm to expect to see a vats signal and will not cut injector pulse. The enable relay doesn't need to be bypassed doing a resister but it's a common failure item.
Joined: Dec 2004
Posts: 16,771
Likes: 1,001
From: Mile High Country !!!
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: Vats or not Vats?
Another option is to feed the ecm a hz signal that it's expecting from the passkey module.
http://m.ebay.com/itm/GM-VATS-or-PAS...%257Ciid%253A8
http://m.ebay.com/itm/GM-VATS-or-PAS...%257Ciid%253A8
Supreme Member
Joined: Apr 2006
Posts: 4,482
Likes: 10
From: Northern, CA
Car: 1989 Iroc-Z Camaro
Engine: TBI,5.0
Transmission: Automatic 700R4
Axle/Gears: Eaton Posi,3.42,LPW Ultimate Cover
Re: Vats or not Vats?
In the end, after messing with VATS and a few other problems I finally had "Tuned Performance" reprogram my "EPROM" and had a few other items changed and its one of the best things Ive done for my car.
He's a really great guy to work with.
He's a really great guy to work with.








