I got a chip made for my 86 and the vats was disabled. When I try to start the car with my new key that I got off ebay with some random pellet in. The car won't start and then it won't start with my old key until I unhook the battery. I asked the guy I got my chip from and he said their is a relay that has to be bypassed.

Last time I had a vats tpi car(trans am) I just bought a bypass module off ebay and wire it in. I guess I assumed the chip disable would do the same pretty much

Anyone know where this relay is?

 

Think I found my answer.

http://www.joestradingpost.com/vats/

 

You need to get a vats bypass module in the code of the original key..If you don't know the code number of the original key you can either use a multimeter to check the resistance, and then use a vats chart to figure it out, or you can go to a GM dealer and they can read it for you... To be truely rid of the vats you have to , Have it disabled in the memcal, install a vats bypass module , bypass the start enable relay.. Unless you do all three things you still have some parts of vats working..At least you have the hardest one done first, which is disabling it in the chip..... Here is the site that tells how to completely remove vats forever.......WW

http://vatssucks.com/?hg=0&nr=0

 

Ok I used a vats bypass module before on a car only and so what is the point of disabling it in the chip if you have the module? In the past I've always read chip or module not both!

edit: The module I used was one I got off ebay that figured out the correct code and spliced in the wire by the ecm. So if it's fooling the ecm why do I need the chip disabled?

 

VATS does two things. Enables the starter and sends a signal to the ECM. If the ECM does not see that signal it does not pulse the injectors.

The VATS module measures the resistance of the key pellet and then enables the starter and sends a signal to the ECM. In 1990 the VATS function was moved into the PCM and there is no separate VATS module.

In most cases the VATS kicks in because there is a problem in the key pellet part of the system. That could be a dirty pellet in the key so it doesn't make a good connection. The contacts in the ignition cylinder can go bad (I had one bend over). The wires from the ignition cylinder are very small and they can break because they get flexed every time the cylinder is turned.

The most common VATS bypass involves simulating the key pellet by putting a resistor with the same resistance as the key pellet into the connector at the base of the steering column. This connector is easy to find because the plastic sleeving on the wiring harness is orange:



You unplug the connector and put the resistor into the connector in place of the VATS key pellet wires (the small white wires). The usual method is to cut the white wires and solder the resistor to them. The key pellet resistors are 1% values but you can use several 5% values to get close enough.

VATS can be disabled in the ECM code, but that only enables the injectors. It does not enable the starter. To do that you need to bypass the VATS starter enable relay. In 1986 - 1989 cars it is behind the center cluster (the relay with the large yellow wires). Connect the yellow and green/white wires together:



In 1990 and later cars the relay is mounted on the firewall at the base of the steering column.
.

 

If it is programmed out of the memcal, and the yellow wire at the relay is grounded then VATS has been eliminated, and your posted link will confirm this. You may also chose to eliminate the relay and bypass it entirely. Up to you!

 

Thx for clearing it up Cliff Harris

 

This thread is old but but pertinent to my new to me 89 Vette. Thank you for the detailed write up Cliff H. Much appreciated!

Cheers and ride safe!

 

I removed the start relay out of my 87 and connected the wires together.I measured the resistance on the key pellet and bought a resistor assortment for $8.No more vats problems.Easiest no hassle fix is just putting a resistor on the wires in the orange cover.