Valkyn71

My car has been acting very strange. When I try to start it, everything is normal, i have all power accessories, but when i turn the key the car wont crank.

I replaced the ignition switch, and the problem remains.

I have had problems with the VATS not letting me start the car in the past, but then the sercurity light would flash. Now it is on, but not flashing.

So now i want to bypass the VATS by jumping the yellow and purple wires in this diagram: http://shbox.com/1/pass_key.jpg

If this is the problem, the car should crank but not start, then I can have my tuner program out the fuel shutoff and be good to go, in theory.

My problem is i cant find exactly which wires i need to jump? Under the dash are serveral different sets of yellow and purple wires. Can anyone point me to a picture that shows the ones i need? Can they be seen in this picture? http://shbox.com/1/air_bag_disc_2.jpg

Is it possible to access the VATS module from under the steering wheel area? Or do you need to remove the lower dash pannel below the glove box?

Thanks in advance.

jtblckmaro

Just pull the panel under the steering column. It's right there. Piece o' cake. Just did mine couple of weeks ago.

shoebox

The theft deterrent relay is to the right of the glove box. That is where the yellow and purple wires are (there is also a hatch relay there). You better know what you are doing if you are getting into this. Bypassing the TDR only allows the engine to crank. It does not completely bypass VATS.

Valkyn71

Having the fuel cutoff programmed out o fthe PCM in addition to this would completely eliminate the VATS correct?

shoebox

Yes, but it won't get rid of a security light if you have one.

Valkyn71

Shoebox, could you please circle which are the correct yellow/purple wires in this picture? (view from where the glove box normally is btw)

95LT1Z28

To bypass VATS and make the TDR think that the system is good to go just wire in the resistor(s) (use an ohm meter on the resistor in your key to find out what resistance you have). Cut where the orange covered wires are and solder your resistors in place. This will make the system think that your key is in the ignition with the correct resistance at all times. This should turn off the Security light and fix any other starting related problems that you are having.

Jeff

Valkyn71

I've done this before and it didnt work. Im not sure whats up with my VATS. I would rather just totally bypass it.

95LT1Z28

Hmmm... Are you sure the resistance is the at the correct ohm's? I bought my '96 Z28 used and the guy who had it before me replaced the BCM and did a hack job bypassing the VATS system. He had it bypassed around the TDR which in the '96 is located in the BCM. I had to go through all 15 resistor combinations before I was able to find right one to bypass the whole security light/fuel shut-off ordeal. The resistor method is the easiest and cleanest way to bypass the system before you start tearing into bypassing the TDR altogether. Good luck!

Jeff

Valkyn71

I measured the resistance of the pallet on my key, bought some resistors at radio shack and wired it into the the correct place. The security light never went off, and later the resistor fell out completely, leaving the two wires not hooked to anything, and the car would still start normally and the security light stayed on.

95LT1Z28

I would try the different resistor combinations just to see if you can get that light off. Usually car audio install shops carry the 15 different resistors in a pack for around $15-$20. As to bypassing the TDR itself, I am not too sure exactly what all you have to do. Good luck and hope you get things dialed in!

Jeff

Valkyn71

I've discussed bypassing the VATS in the method in previous threads with Shoebox, i think he was the one who suggested it was possible.

Jumping those two wires should allow the car to crank, then having the fuel cutoff removed from the PCM should allow the car to run.

FirebatLT1

All the vats module does is make the yellow/black wire on the TD relay have ground(if you program out VATS) and makes the security light work. Just hook yellow/black wire to ground, remove the VATS box but you won't have a security light. I know this works.

You could go a step further and bypass the TD relay(since you removed VATS - the only reason for having the TD relay) by removing the TD relay and connecting the purple and brown wires together that are located where the TDR would be.

shoebox

The TDR is not in that pic. It is directly to the right of the glove box. You have to stick your head under the dash and look backwards.

RE AND CHERYL

If you install a resistor in line you have to either have a key made without a resistor or disconnect the wires going to the resistor contacts in the ignition lock.

I've got a dealer manual for a 94 with has the sane system, I'll look in it and see if there is a easy way to bypass it.