VATS By-Pass Procedure

Vehicle Anti Theft System

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The example used here is for GM vehicles from 1988 through 1996. You can identify a VATS systems by the fact that the key has a visible "black chip" on the shaft of the key. The keys used can have either a single side cut or have key cuts on both sides. Both styles used VATS.

Determine the Value

The first thing we need to do is determine the resistance value in your key. There are 15 different possibilities. There are 2 ways to read this value.

Your key can be "read" in a VATS tester. Most locksmiths have these readers, and don’t charge anything to tell you the value of your key. Below is the conversion chart to convert the number the locksmith will tell you to the Ohms value you will need to know.

1———— 0.402
2———— 0.523
3———— 0.681
4————-0.887
5————-1.130
6————-1.470
7————-1.870
8————-2.370
9————-3.010
10————3.740
11————4.750
12————6.040
13————7.500
14————9.530
15————11.801

The other method is for you to read the key value yourself. If you have a Volt-Ohm Meter you can test the OHMS (resistance value) of the chip yourself. Just set your Volt meter to check OHMS, take each lead and place it on each side of the "chip" on your key. Make sure not to touch the key shaft itself.

Okay, now that we have the ohms value, we are going to duplicate that resistance value and solder in a resistor in the car, thus eliminating the steering column and VATS key circuit. You will still need your key to turn the car on, but it will no longer need to read the chip.

Here are the tools and supplies you will need:


1. Soldering Iron
2. Wire Cutters/Strippers/Crimper
3. Heat Shrink Tubing or Electrical Tape
4. The Resistor matching the value measured across your key's "chip")

You can purchase the tools, resistor and heat shrink tubing at Radio Shack. If you cannot measure the resistance and you cannot find a locksmith to tell you the code value to translate it to a resistance value, ask the people working at Radio Shack to measure your key and duplicate it with a resistor for you. They will certainly have a meter to accomplish this.

Now Move to the Car

Remove the under-dash kick panel on the driver’s side. Look for an orange wire running down the steering column and into a connector (either a small 2 wire connector or a large bulk connector). Here are a couple of pictures of what you are looking for. This orange wire should have a "rubbery" feel to it, and it is the only thin orange wire running from the column.




**WARNING** Do not tamper with any of the wires near the column wrapped in yellow harness tape or any yellow wire. These wires are for the airbag. Tampering with any of these wires could result in the airbag discharging.

Install the ByPass

Once you are confident you have located the correct wire, cut it with plenty of room on either side. When you cut it, you will find 2 smaller white wires inside. On the dashboard side of the cut (not the end going up the steering column, but the other end) strip back the insulation on the wires. Strip back enough wire to solder a connection. We are going to insert a bypass for the car to read --- eliminating the column side of the wiring.

If you are using heat shrink tubing to insulate your connection, slide that on first. If you are using tape, go right to the next step.

Carefully solder in the resistor from one white wire to the other as shown.

Now, attempt to start the car. If your problem was with the VATS reader in the ignition lock cylinder, the car will start.

Lastly, simply finish insulating your connections and reassemble the car

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