Bypass VATS

[Darren]

So Nate did it work, get her running?

[nascarnate326]

Cant go on lunch till the high school lunch time. So here in a few min I will head out and give it a try.

[nascarnate326]

Did not work. hmmmm

[nascarnate326]

I dont think I did it right.

My key is a 14 but when I checked the resistor value it was 9.9 the thing i made measured in at 9.79. I think i didnt test it correct.

[prorac1]

Good luck

[9T8W66]

This is one of the better write ups for the VATS Bypass.
http://www.ls1.com/forums/showthread.php?t=61262

[nascarnate326]

OK, thanks Craig.

Because my car is a 14 it needs 9530 of resistance. Anywhere from 9149 to 9931 should work because of the 2% margin of error.

Two of these 4.7k resistors should equal 9.4, falling in the range of "working" resistance allowing my car to fire. The one I tried today was above the range. I went based off what my key said, not what the internet/GM said.

Does this sound like I am on the right path?

photo..jpg

[98blackbeauty]

Nate, doing the "vats bypass" is only bypassing the key. You already stated you bought and tested a key at dealer. cutting the wire and installing the resisters bypasses the key, If your module is bad a new key or bypass will not help. Once the module detects the correct resistance from key or bypass resisters it sends pulse to PCM which turns on fuel pump and fires injectors. Hopes this helps you understand this system better.

[nascarnate326]

Nate, doing the "vats bypass" is only bypassing the key. You already stated you bought and tested a key at dealer. cutting the wire and installing the resisters bypasses the key, If your module is bad a new key or bypass will not help. Once the module detects the correct resistance from key or bypass resisters it sends pulse to PCM which turns on fuel pump and fires injectors. Hopes this helps you understand this system better.

I am slightly confused what you mean. Module as in the part that reads the key? If so thats the part that is bypassed

What should I do now?

I am thankful for your help.

[prorac1]

Theres got to be someone on this site with OBD2 tuning software that can just turn off vats. I left mine on cause it still works, but i had the option of tuning it out. Thats my guess. Eric L

[meissen]

Nate, doing the "vats bypass" is only bypassing the key. You already stated you bought and tested a key at dealer. cutting the wire and installing the resisters bypasses the key, If your module is bad a new key or bypass will not help. Once the module detects the correct resistance from key or bypass resisters it sends pulse to PCM which turns on fuel pump and fires injectors. Hopes this helps you understand this system better.

I am slightly confused what you mean. Module as in the part that reads the key? If so thats the part that is bypassed

What should I do now?

I am thankful for your help.

If I'm understanding the bypass correctly, my dad makes a good point but it's still worth a shot. The bypass is because the contacts in the steering column are not reading the key's chip/resistance correctly. Sometimes it's the key, sometimes it's the contacts. Because you bought a new key, it's definitely not the key that's bad - it's either the contacts in the steering column / key tumbler or it's the VATS module itself. If your bypass works, the problem was in the steering column. If the bypass doesn't work, the problem is the VATS/BCM module itself.

[nascarnate326]

My dad got it to work with the resistor trick and the key wires all hooked up. So basically added a resistor to the stock setup, works great.

Makes ZERO sence, but it runs good now.

[98blackbeauty]

nate go to shbox.com you'll see the wire diagram for the vats system, then you'll understand what the fix did. Sounds like the contacts in the ignition lock unit were bad.

[Curt_irocz]

When they first came out with the VATS in 1989 in Camaros/Firebirds. It was much more simple. You just had to take the yellow wire that comes from the steering column, that goes to the VATS box. Then take the purple wire that comes out of your VATS, and cut them and connect them together. So basically they just stuck the VATS box into the S terminal. So if the VATS got the Correct OHM'S resistance It would start, But you could just do like I said and that completely bypassed it. So im guessing that they changed it in later years?

[nascarnate326]

Vats came back to haunt me. Some how we have the exact same resistance with resistors and it doesnt work. The key switch is working, hooked it all back up as stock, no fire. All our measured values are exactly what they should be, car doesnt start. All I can think is that a wire may have got pulled on too hard(doubt it) and isnt connecting to the PCM.

I ordered a bypass module so I can just get rid of the entire system. Im so fed up with this car.