I have a 92 RS with the 305. It refused to start so I checked all the usual suspects until I got to the VATS. When I bypassed the starter enable relay the engine cranked but would not supply fuel, which seems to me to indicate a fault with either the key or the VATS box. I then realized that the 'SECURITY' light never comes on, even in bulb test, which the factory manual says it should.

I went to my local Chevrolet dealer, who told me that the VATS box is on backorder and it costs $312. Ow. Furthermore, my understanding of the VATS system is that if I get a scrapyard box, I will have to change my keys, which will cost more money. Since no one is going to steal an 18 year old $650 car, I would like to get rid of VATS for good if I can do it for cheaper than getting a new VATS box.

I was reading and it says in the tech info that Pass-key was introduced in 1989 and the LO3 engine came out in 1988. I don't want to get into burning custom chips just yet, so can I swap my PROM for one from a 88 Camaro with LO3 to disable the VATS system?

 

Can anyone shed any light on this? I know the speedometers are different, are there any other potential problems with this?

 

A on TGO would have given you these, without having to wait for somebody to see your Post & respond.

VATS bypass

Or....

VATS Bypass II but I know little about thhis one.

 

That technique for bypassing the VATS doesn't get rid of it for good. (Assuming that the first link is also for the resistor method, it won't let me look at it at work.) It just tricks the box into thinking that a good key is inserted. I want to completely get rid of the system because I think that the box itself is bad and I don't want to pay $312 for another one.

I know that there is a flag in the PROM that can be changed to disable VATS, but I don't have the equipment or expertise to program my own chips yet, and I need this car fixed soon because it is (was) a daily driver. Hence my question about whether a stock chip from an earlier model year would work in my car as a temporary solution.

 

To bypass VATS completely you can get a module that supplies the fuel enable signal needed by the ECM .
http://www.fieroaddiction.com/passkey.html

Have to manually bypass the starter enable relay

Or just buy a custom chip with VATS deleted
http://www.pcmforless.com/index.php?...128&Itemid=341

 

Thanks vetteoz, that is what I was looking for.

 

bump

 

Bump for what ?
Question was answered

 

I was just making it more resent and easyer to find while I work on my car.No harm intended

 

That is why you bookmark (save ) the page on your web browser;
can bring it up years later

 

I have a 92 RS it had a 305 tbi. I pulled the motor and put in a 1988 350 tpi. Even with the pre vats motor it will not start without the vats key. I think because the interior harness still routes through the vats module? As far as I know as long as the module is there the computer still needs it to start.

 

Nothing to with the motor year
Unless you bypass the starter part of VATS in a car originally equipped with VATS , ( smart people know to do this )
the engine will not crank over regardless of what year engine you have ; nothing in the car itself has been changed

The programming in the computer ( prom ) determines if VATS is required or not .
A non VATS prom in the computer will allow the engine to fire up regardless of whether the VATS module is in place or not.
Taking the module out of the car on a computer with a prom that is looking for the fuel signal from the VATS module will solve nothing ; it still won't start.