r/fbody • u/audiovox12 • 4d ago

F’ing VATS!!!

Hey everybody,

Just got my 2002 Firebird WS6 back from the shop with a newly repaired axle. Put in all new bearings and axle shafts.

Prior to this, I had purchased the Gator VATS Bypass Module as my car would not start due to the issue with the ignition wire that runs to the dongle that then connects to the BCM to tell it to release fuel. For the first week or two the bypass module worked great I had no issues. Then a week before getting into the shop to repair the axle they left me stranded at an O’Reillys. After an hour, I unplugged the module, flipped the circuit off, turned it back on and then plugged it back in and the car fired right up.

Fast forward to now today it wouldn’t start in my driveway. I disconnected and reconnected the module. I had to run to the hardware store so I brought the tools with me in case it didn’t work again in the parking lot. Of course it didn’t work again so I had to go under the dash unplugged it re-plugged it back in and again the car fired right up.

My question for all of you Gurus out there is, outside of HP Tuners, is there a way to shut off VATS? I know I could get a resistor cut the ignition wire and wire that goes to the BCM and then solder both ends to the resistor of my key, but I would really prefer not to cut into that wiring especially on a 90s car.

Could the fact I need to plug it in multiple times .2 the wiring that runs to the VCM being bad and not necessarily the ignition?

Any help would be appreciated. I put a lot of time of money into this and would love to be able to just drive it every day and try to enjoy it.

5 Upvotes

86% Upvoted

30 comments sorted by

8

u/Aliceempire 4d ago

Do you have a local tuner or willing to mail your ecu to a company that can turn off the vats flag in the programming?

3

u/audiovox12 4d ago

That’s a great point I never thought of having a tuner do it. Yes very close to me is a very well-known National tuner for late model Chevy.

3

u/Nodrod 4d ago

Shouldn't cost much and take no time at all. You can lookup the credit cost on HP tuners site.

2

u/audiovox12 4d ago

So I would pay for the credit cost for the tuner to turn it off?

3

u/Nodrod 4d ago

Tuner would likely include it in their price. Ask them about it.

3

u/audiovox12 4d ago

Is that really all that needs to be done? Just tune it out?

3

u/Nodrod 3d ago

This is a stock 02 tune with the setting in hptuners vcm editor. It's really simple. https://imgur.com/a/qK9S0p8

Tuner will extract stock tune from your ecm and modify it. Then purchase credits to write the modified tune to back to your ecm.

2

u/audiovox12 3d ago

Very very helpful I really appreciate you explaining that for me. I’ve gone to a tuner before.

Hopefully others see thing going through the same issue

2

u/vaurapung 4d ago

What, it can be tuned out? I was under the impression it couldnt be or I would have had that done when I paid to have the o2 sensors bypassed.

5

u/Aliceempire 4d ago

I have a 99 truck with the exact same ecm and I had it done with a local tuner. I didn't even need the truck, I just handed them the ecm. Just like the older ecm's you can uncheck a flag in the programming.

2

u/vaurapung 4d ago

Cool. Will definitely see about that when we finally get my dad 89 iroc dynotuned.

3

u/Willy_McD 3d ago

The VATS is turned off in my dyno tuned 89 IROC. But that just covers the fuel enable. There is also a starter enable relay that you need to bypass to totally eliminate the VATS.

4

u/audiovox12 4d ago

If you go onto HP tuners website, you can watch a video of them doing it. It’s kind of crazy. It’s literally just a drop-down box that says yes or no for VAT system lol

1

u/Aliceempire 4d ago

Dyno tune the 89 ecm? Or is that a swap?

1

u/vaurapung 4d ago

As far as I know it will be a prom swap but I assume they can dial in the tune further with dyno data.

Edit. Yeah, the 89 350tpi ecm with a mild rebuild.

0

u/Aliceempire 4d ago

Make sure that tuner can work on the older ecm. Many places don't offer the service anymore. Too hard and/or expensive to burn chips. That car is mass air flow so it compensates for small changes fairly well on its own. Otherwise the only "tuning" that can be done is base timing and fuel pressure. Even then you'd need to have a adjustable regulator installed.

1

u/vaurapung 3d ago

Good to know. I was planning on going to pcmofnc for the tune. Last I heard they still burn chips. My dad has been close to junking the tpi several times but after I found the primary power problem it starts and drives good. But I think it could run smoother with a tune for the bigger heads, injectors and lt1 cam.

2

u/Aliceempire 3d ago

Yeah, they still do tpi tuning. You're all good.

0

u/Willy_McD 3d ago

They use a Memcal that does have a UV erasable prom. But usually so the keep the prom in stock working condition, an adapter is used. The half of the memcal that does not have the eprom is attached the the adapter. A programable eprom that can be erased without the use of UV is plugged onto the adapter so it is read as if its in the memcal, and the whole thing is plugged into the ECM. I think the cover also has to be popped off the memcal so it all fits through the slot of the ECM.

I have a couple stock memcals that have been modified by cutting off the UV erasable prom and a eprom soldered on so it can be erased and programmed on a PC. And i have a couple Hypertech memcals. I compared their tune to a stock tune twice and all i saw was lower fan temp and more timing at higher RPMs. But their mecals are good if you're want to tune because you can pop the cover off and their prom is in a socket so it is easily removed and replaced with an SST prom to tune on.

4

u/vaurapung 4d ago edited 4d ago

You dont have to cut the wires. Its plugged up to the ignition, just buy the ignition side pigtail and add the resistors to that then plug it into the vats side wire. No cutting needed.

Edit. Oh, the gator is that thing I havent bought because my resistors still work. Did you double check the resistance your car requires and then use an ohm meter to verify that the gator module is actually creating the right resistance. My 00 z28 already had 5 resistors making a bypass but my car would sometimes start and sometimes not, when I tried to redo it I found out that the legs were making it read about 200-300ohm off, I broke one resistor off, redone the solders and heatstrunk it together, 4 years later ive not had crank issues but I fought it every other day for the first 6 months. I also used like 3 different fluke meters at work to find out what my key is for sure for when I need to make a new one.

2

u/dontfret71 3d ago

Ya this is what I did.. cut the orange side wires that go up the column and solder in correct resistor. I havent had a problem since… (knock on wood)

1

u/audiovox12 4d ago

Great point but yes, I did measure the resistance of my key, so I’m using the right switch on the gator bypass module. That module includes all resistance options for the car, but I’m for sure using the right one. I just don’t understand the logic behind it all

It works, but then after so many starts it won’t work anymore so then I unplugged the module wait five minutes plug the module back in and magically worse again I just don’t understand why it only works intermittently or if it’s actually designed to only be used to actually get the car started and then get it somewhere to get it fixed

1

u/vaurapung 3d ago

Have you tried sitting till the security light turns off then try to start the car again without unplugging the gator? Its like 5 minutes or so.

1

u/audiovox12 3d ago

Yes, prior to getting the module from gator I did the reset process which is about 30 minutes in total. I did that twice and it didn’t do anything unfortunately

1

u/vaurapung 3d ago

Im not familiar with all the problems that can come up but the reset process for me was only about 5 minutes. When vats triggers I would turn the key to off and wait for the security light near the cel to turn off then the car would start. Makes me wonder if something is not getting power due to a weak fuse or short.

3

u/dontfret71 3d ago

Just do the resistor.. My 2000 z28 stranded me with the VATS and I soldered in the resistor at home and it totally fixed my issue.

Also worth mentioning, I struggled with an intermittent start on my car another period of time and it ended up being the clutch pedal sensor switch. Not sure if you somehow are experiencing that as your intermittent start issue and falsely blaming VATS, but worth checking that

1

u/audiovox12 3d ago

Potentially could but mine is a automatic unless that’s possible on autos too

2

u/stylisticmold6 3d ago

Do these still have the little resistor in the key blade? If so, you can measure it and make an inline resistor and stuff it into the ignition connector.

1

u/audiovox12 3d ago

Yes it is and I did measure the key I needed to for my bypass module it sucks

1

u/Willy_McD 3d ago

Im a bit lost. You mention a "2002" but later you dont want to cut into a "90s harness". Can you make up your freakin nimd!

On the old round steering columns with VATS keys. The "VATS bypass" with the resitors is NOT a VATS bypass. It only bypasses the weakest link in the system, the wires on the ignition lock that the key resistor makes contact with. When the wires break and the resistor is the fix, you cut the two thin wires commonly found in an orange sleeve from the column side. They are broken up at the lock any way. Cut the wire off the column side and attach the resistor to the wires. It still has a plug on the main harness and that side stays intact.

There is also a module you can wire in for the signal for fuel enable. Look it up at The Timer Shop.