VATS disabling
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From: Trumbull County Ohio
VATS disabling
The vats system went a little screwy on my 89 305 rs tbi today. I couldnt start it until i just fiddled around with the vats wiring for a bit.
So basically i'm fed up with this thing. I read the tech article on how to disable it, but it seemed to skip over some things. can anyone who's done it give me a rundown of it?
as a side note...the VATS and PASS are the stupidest systems i've ever heard of. Who's going to steal your car by trying to use the wrong key....?
So basically i'm fed up with this thing. I read the tech article on how to disable it, but it seemed to skip over some things. can anyone who's done it give me a rundown of it?
as a side note...the VATS and PASS are the stupidest systems i've ever heard of. Who's going to steal your car by trying to use the wrong key....?
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Before you go bashing vats, keep in mind that there are a good number of people on this board that wouldn't have their f-body anymore if it weren't for the factory vehicle anti-theft system.
No-start conditions are very frustrating as you're finding out, but vats is not necessarily the cause of all the problems attributed to it. For instance these conditions can cause a no start condition as well:
blown headgasket/engine hydrolocked
bad starter
faulty ignition switch
fuel injector wires shorted to ground
bad ecm
.
.
.
and the list can go on for pages
basic idea with the vats bypass procedure your finding written up in the tech article section is to put a fixed value resistor in place of where the key resistance would normally be. can also bypass by electrically jumpering the vats starter kill relay and sending a square wave with the proper duty cycle to the ecm.
having your car towed to the local mechanic shop that does not have any wiring schematics for your car and has not dealt much with vats problems may not be a wise idea. countless people have had their wiring harnesses hacked to peices by such shops. gm dealer is probably the best bet.
No-start conditions are very frustrating as you're finding out, but vats is not necessarily the cause of all the problems attributed to it. For instance these conditions can cause a no start condition as well:
blown headgasket/engine hydrolocked
bad starter
faulty ignition switch
fuel injector wires shorted to ground
bad ecm
.
.
.
and the list can go on for pages
basic idea with the vats bypass procedure your finding written up in the tech article section is to put a fixed value resistor in place of where the key resistance would normally be. can also bypass by electrically jumpering the vats starter kill relay and sending a square wave with the proper duty cycle to the ecm.
having your car towed to the local mechanic shop that does not have any wiring schematics for your car and has not dealt much with vats problems may not be a wise idea. countless people have had their wiring harnesses hacked to peices by such shops. gm dealer is probably the best bet.
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Joined: Oct 2001
Posts: 433
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From: Trumbull County Ohio
well i'll continue to bash the VATS system happily, but thanks for randomly defending it. Theres about 1,000 different ways i can think of to keep your car from being stolen, all of them more simpler and more effective than VATS. Personally i like adding a hidden toggle switch to my fuel pump, its worked quite well for me.
I'm well aware of all the other causes of a no start condition...but i DID trace it back to the VATS system this particular time. I know what the basic concept of the tech article says, i just wanted to get someone who's actually done this to maybe tell me where they spliced they chose to splice the resistor in. anything particular trouble they ran into? that sort of thing...
plus i imagine it would be kind of hard to find a resistor with the EXACT amount of resistance of your key, so how much play do you have? the resistor on mine has 3.725k resistance....i can find a 3.6k and 3.8k resistor....am i going to get away with this?
I'm well aware of all the other causes of a no start condition...but i DID trace it back to the VATS system this particular time. I know what the basic concept of the tech article says, i just wanted to get someone who's actually done this to maybe tell me where they spliced they chose to splice the resistor in. anything particular trouble they ran into? that sort of thing...
plus i imagine it would be kind of hard to find a resistor with the EXACT amount of resistance of your key, so how much play do you have? the resistor on mine has 3.725k resistance....i can find a 3.6k and 3.8k resistor....am i going to get away with this?
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yes a "hidden" toggle switch is much more effective than no security at all. problem is definition of "hidden" often leaves much to be desired, and you have to actively arm the system. does not passively arm like vats.
alarms installed by best buy, circuit city, etc are for the most part just noise makers. many will have a starter kill feature, but it's easy to defeat since 99% of the installs have the alarm brain under the drivers dash.
go look at some recovered theft vehicles, you'd be suprised how easily non-vats equipped general motors vehicles were "hotwired". probably took less than 1 minute in most cases with nothing more than a screwdriver.
anyways, it appears that you've got your mind made up to bypass the vats system instead of fixing it properly.
15 resistor values are contained in this thread:
https://www.thirdgen.org/techbb2/sho...hreadid=103321
resistors with a gold band will have 5% tolerance. if you can't get a value close enough to the values listed, you can apply "ohms law" and combine resistors in parallel and series. if not familar with ohm's law, type "ohms law" into your favorite search engine and you'll find more than enough info.
vats decoder module has been known to fail too. if you look in the schematics, you'll find a wire that runs from the decoder module to the ecm. if you hook up an oscilloscope, this wire should have a square wave on it when the proper resistance is seen by the module and the ignition key is in the on position.
alarms installed by best buy, circuit city, etc are for the most part just noise makers. many will have a starter kill feature, but it's easy to defeat since 99% of the installs have the alarm brain under the drivers dash.
go look at some recovered theft vehicles, you'd be suprised how easily non-vats equipped general motors vehicles were "hotwired". probably took less than 1 minute in most cases with nothing more than a screwdriver.
anyways, it appears that you've got your mind made up to bypass the vats system instead of fixing it properly.
15 resistor values are contained in this thread:
https://www.thirdgen.org/techbb2/sho...hreadid=103321
resistors with a gold band will have 5% tolerance. if you can't get a value close enough to the values listed, you can apply "ohms law" and combine resistors in parallel and series. if not familar with ohm's law, type "ohms law" into your favorite search engine and you'll find more than enough info.
vats decoder module has been known to fail too. if you look in the schematics, you'll find a wire that runs from the decoder module to the ecm. if you hook up an oscilloscope, this wire should have a square wave on it when the proper resistance is seen by the module and the ignition key is in the on position.
Last edited by 2vmodular; Jun 4, 2002 at 10:52 PM.
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