1bad66ss

iTrader: (1)

Hi guys, new to the site, but long time reader. I just picked up a 89 iroc project car, and as you can guess it won't start. I've spent a number of hours reading/searching on the dreaded VAT monster. The ignition switch has been removed, and is no longer functional. It came with a key but it will no turn the cylinder. I have tried checking the ohms on the chip, but I'm not getting any reading. It looks as if the po tried to punch the chip out of the key.
Any suggestion on how to get this thing started ?

Sonix

iTrader: (1)

call up GM with your VIN and get them to make you a new key. Check the resistance of that key, and either bypass vats, or use the new key.
Or buy a new ignition cylinder, without vats.... I think you may still need to know the resistance of the original chip though...

camaronewbie

There are only 15 various resistance levels - you could spend $15 at Radio Shack and get each resistor, trying each until you found the right one. Of course, you'd have to have the key blank to turn the ignition cylinder at all. But for $15, you know what resistor is required, and you could then get a whole new cylinder ($50 at Carquest), and have a chipped key made ($20 at Ace Hardware) - all total probably less than the stealership will charge you!

The values and the bypass info:

http://vats.likeabigdog.com/

FUNIROC

iTrader: (4)

If you find the proper resistance for your key. Then look on ebay the vats keys go for about $13 a set for the blanks. I got my extra that way and Lowes cut it for free.

INSTRUCTIONS
SET OHM METER TO 20-K
TAKE ONE OF THE LEADS OF YOUR OHM METER AND TOUCH THE METAL PRONG ON THE KEYBLADE. TAKE THE OTHER LEAD AND TOUCH THE OPPOSITE SIDE AT THE SAME TIME.THIS WILL GIVE YOU A READING BETWEEN .386-12.290.READING MIGHT NOT BE EXACT BUT CHOOSE CLOSEST TO VALUE.

Here is what you are looking for.

VATS# ------------------------- Resistance
1----------------------- .402 .386-.438
2----------------------- .523 .502-.564
3----------------------- .681 .650-.728
4----------------------- .887 .850-.942
5----------------------- 1.130 1.085-1.195
6----------------------- 1.470 1.411-1.549
7----------------------- 1.870 1.795-1.965
8----------------------- 2.370 2.275-2.485
9----------------------- 3.010 2.890-3.150
10----------------------- 3.740 3.590-3.910
11----------------------- 4.750 4.560-4.960
12----------------------- 6.040 5.798-6.302
13----------------------- 7.500 7.200-7.820
14----------------------- 9.530 9.149-9.931
15----------------------- 11.800 11.320-12.290

1bad66ss

iTrader: (1)

Thanks for the responses guys, I have read up on those two sites before I posted the question. Unfortunately I'm not getting a ohm reading from the chip in key. The po tore the cylinder out of the column, well not really tore but forcefully removed ha ha. At this point I'm not concerned about repairing that, but would like to see if I can get it to start. I can reach into the column with a pair of pliers to turn the ignition on, but need to find out what the resistance needs to be. Can the vat module yield this info?
Thanks

FUNIROC

iTrader: (4)

The following is from the GM service manual.

Tool Required:
J 35628 VATS Interrogator
To replace lost VATS ignition keys it is necessary to determine the mechanical cut and the electrical (resistance value) code.

FUNIROC

iTrader: (4)

The following is from the GM service manual.

Tool Required:
J 35628 VATS Interrogator
To replace lost VATS ignition keys it is necessary to determine the mechanical cut and the electrical (resistance value) code.
The mechanical cut can be determined from the key code on the ignition lock cylinder or from the original key "knock out". If the mechanical cuts cannot be determined, the ignition lock cylinder must be replaced. Make a key with the correct mechanical cut to use while determining the proper electrical (VATS) key code.
To determine the proper electrical key code (resistance value) use J 35628 and the following procedure:
1. Connect J 35628 wiring to the VATS dash connector at the base of the steering column. Do not connect the steering column wiring.
2. Turn power switch "ON" and place key code switch to "1" and attempt to start engine with proper mechanically cut key. If engine starts, the key code is "1".
3. If engine does not start, press four minute timer.
4. When timer lamp goes on, or the "START CAR" message is displayed, place key code switch to "2" and attempt to start engine. If engine starts, key code is "2".
5. Continue trying different key codes until proper key code is found.

FUNIROC

iTrader: (4)

It also looks like you can change out the Lock Cylinder and key. Plus the VATS module and then once installed the VATS module will learn the new key code. It also says if you do this the VATS module will read it the first time you try and then it is set permanently. So it said caution to make sure you use the proper key the first time the VATS module gets power.

Atilla the Fun

You can cut the 2 wires going to the cylinder, then solder the Radio Shack resistor into the 2 wires going to the cylinder, and use keys with no resistor. I did this to my sister's '90 Firebird. Problem solved for $12.

1bad66ss

iTrader: (1)

The plan today will be to hook up a 20k potentiometer up to the two white wires, which I assume were attached to the ignition switch at one time. This way I can adjust the dial till I locate the correct resistance value. If this works it should save a little time by not having to switch out resistors each time.

Toehead

That sounds like a plan. Make sure to wait the four minutes between each attempt.

1bad66ss

iTrader: (1)

I've wrenched on cars most of my life, but this is my first attempt at getting a computerized car to run. Bad thing is the po has torn the ignition switch out, plus the chip has an open in it so I have to do it the hard way. Hopefully this will work and then I can put the correct resister in place of the pot. Wish me luck
By the way, thanks for all the help guys.

1bad66ss

iTrader: (1)

Good news! the potentiometer made the job a lot easier than swapping out resistors. It ended up being 1.870 ohms, although the car is not running yet it will turn over. The car has sat for a few years, so I'll have to see if the fuel pump is running then put some fuel in it. Seems to have a good spark, so I sprayed a little fuel in the TB and it ran for a 1/2 second.

Toehead

Good! Congrats!