ok I haven't seen any threads on this or stickeys....heres my question..I have an 89 trans am..I'm doin the LSX swap, damn near done too..I have the original key from the 98 camaro I pulled the motor from..if I go to chevy and get a key with the same code as the 98 and cut the key to the original key I have with my 89..will it fire..I really don't want to disable vats..this seems logical..just hopefully the vats module doesn't want to see something else then what pats wants to see..do both of these modules work off of resistance..neways any help would be big help in finishing this thing up..thanks..

 

Great question, I'd be interested to know as well.

 

Wish it was that simple.

Unfortunately, the thirdgens, and the LS1's have completely different Vat's setups.

Thirdgen VATS' use a seperate module to disable the fuel injectors if the wrong key is in, while the LS1's use a serial VATS that is in the LS1 computer.

If you could find a way to have the thirdgen module communicate with the LS1 computer, it may be possible, but reality is, its a ton of hassle, and you'd save yourself time and headache to just setup an aftermaket Anti-Theft system.

 

ok then if that is the case..why don't we just get rid of the third gen module and wire it straight up..then all the ls1 computer would see is the right key and it should crank..I really wonder if anyone has tried that yet..

 

also where is the vats module on third gens...preferably 1989 pontiac trans am GTA..

 

See if you can find a schematic for the LS1 Vats system.

For the camaro's, its bolted to the back of the HVAC Vents behind the dash, need to remove the dash to get at it.

Heres what i can say from experience. i deleted vats in my computer tune. When i had the dash out of the car last year, i got curious, if the original engine harness is gone, what if i disconnect the vats module, will it run properly.

Findings was, i turned the key, and nothing. Seemed to cut the ignition output to the engine harness power.

Now im not sure what you can take from this, but that made me content that my chipped key was still required to provide IGN + volts to my fuse box.

So, from there, you can decide, but i think it functions, but in a different form so to speak.

 

ok so you disconnected the module..but did you ground the wire out..I'm looking at a 1990 haynes manual schematic ..it showes the ignition switch first..then switch it to run and you get power to the starter enable relay, which looks like to me gets grounded by the pass key decoder module..maybe vats just acts like a ground to power the relay..hopefully I should just ground that wire..or I could get a little resistor and wire that in before the module...take the module out and simply ground the wire...maybe??

 

If the module grounds the starter enable relay, that means 2 things.

To remove it, you would just need to connect the input and ground wire, essentially bypassing the module?

Second, the factory chipped key, if not identically duplicated, means the starter enable relay cannot be grounded. So it still functions as a type of VAT setup?

Perhaps you can run both? If you can figure out a way to make the thirdgen module still recognize the 98 key, that would ground the starter enable relay, then when the computer see's the 98 key, it is willing to ground injectors.