VATS by-pass

[jerrymacdaddy]

I by-passed by VATS about 1 year ago and was having great luck until recently. About every other day my car will not start on the initial try. The security light comes on and then I'll wait for 3 minutes until it goes out and the car will crank without a problem. Any ideas as to what is going on and how I can correct?

[clm2112]

I by-passed by VATS about 1 year ago and was having great luck until recently. About every other day my car will not start on the initial try. The security light comes on and then I'll wait for 3 minutes until it goes out and the car will crank without a problem. Any ideas as to what is going on and how I can correct?

Hmmm, check the connections on the resistors you inserted into the circuit yet? Perhaps a solder joint has come apart because it is acting in the same maner as if the VATS module saw an open circuit or wrong value from the key wires.

[92 White ssei]

I am trying to install vat bypass module i bought form baker electonix 1992 ssei .
i can't locate the tdm module behind the glove i took it nothing there
air bag is there

[willwren]

92, please start your own topic with your problem. That's the respectful thing to do rather than clutter Jerry's topic with your problem.

[Bob Dillon]

Replace the resistor. They're about 5/$1.00 at Radio Shack. I keep them in the glove box.

[jerrymacdaddy]

I removed the by-pass and tested it and the numbers are where they need to be. I did notice there were a couple of strands of wire exposed from the VATs so I made some corrections and it has started with no problems. If I have future problems I'll go ahead and replace the resistors. Thanks for all the advice.

[sonoma_zr2]

The VATS wire are so small and fragile, that even with the connections soldered, they will still break. They also take more heat to solder than the resistor leads, leading some to believe they are soldered, when they only have a cold solder joint.

[sandrock]

The VATS resistor trick only works if the VATS module is working correctly. It's not a true bypass, more of a trick than anything.

It's easy enough to bypass the VATS starter portion of it. I don't have the pinouts with me, but on the transmission P/N switch, you will find a small-gage yellow/blk wire. Snip it, and run the switch side to a good ground. This enables the starter relay to function without the VATS interfering with it. If the "fuel enable" portion of the VATS module is working correctly, this will be a near-total bypass for you. If the "fuel enable" part is toast too, you will need to take the fuel pump relay off of PCM control.

EDIT - A little background on the VATS module. A NEW module will learn the key resistor value the moment it initially powers on, and it's permanently encoded from that point forward. And of course, no new ones are made anymore. You can swap a known good used unit in, IF it has either the same value as your key, OR if the key from the donor vehicle is also sold with it...the resistor pellets can easily be swapped between keys, or just do the resistor trick after measuring the pellets resistance.

[sonoma_zr2]

When messing with my column swap I did the trans p/n wire ground. Is allowed the car to start, but shut off after 3 secs. That is a quick way to test things, but is not a complete bypass.

[sandrock]

No, it isn't...it's only a partial. A full bypass would be that plus one of the following:

1) Change the settings in the PCM to ignore the VATS.
2) Fuel pump relay activates w/o PCM telling it to. Usually means having it to activate in "start" and "run".

FTR, I'm fully off of VATS. PCM is programmed to ignore it, and the yellow/black wire is grounded. VATS module is somewhere in the field behind my house, and nothing replacing it.

EDIT - I am only guessing that the relay being off of PCM control should work. I haven't tried it yet, but the PCM doesn't do anything else OTHER than disabling the fuel pump if a VATS handshake isn't established (when it comes to starting and running that is). Taking PCM control away from the fuel pump creates a small problem though...the fuel pump will continue to run if the engine suddenly stops running and ignition is on (fuel pump shuts off if the PCM detects a no-run condition).