FAQ Frequenly Asked Technical Questions. This section is read only, and posts are made by the staff. If you have something to contribute contact any moderator.

GM Cadillac VATS Bypass - Passkey II - code B2711

Old 04-27-2007, 06:01 PM
Stealth's Avatar
Super Moderator
Thread Starter
Join Date: Feb 2007
Posts: 3,945
Default GM Cadillac VATS Bypass - Passkey II - code B2711

not my words ...

================================================== =======

a quote :

[align=left]-- When you insert your ignition key and attempt to start the car, will the car not even attempt to crank over? Does the "Security" light flash during any time you're attempting to start the car?[/align] [align=left]
[/align][align=left]The simple solution is to first clean off the chip on your key or try another key for the same car. If that also doesn't work, then follow my instructions for a fast, simple, and relatively inexpensive repair."[/align]

in the Allante world, we recommend that no one drives around without this life saver item if your
car has the VATS -
Vehicle Anti Theft System. We recommend it be carried in the trunk for emergency.

This thread does not intent to advice the practice of bypassing the VATS for the sake of bypassing,
but does advice the carrying of a bypass kit that can be used when the wiring to the key mechanism
fails. This is even more important as these 7+ year old cars age and time takes its toll on the connectors, the wires, the key capsule (the chip).

This applies to any and all GM cars with Passkey II - VATS
you may see the dreaded: "CAR MAY NOT RESTART" message, the security light, code B2711.

although it is not stated in the write up of the link to follow, this jumper bypass works for the Allanté as
well as all the GM cars using the VATS system.

here is the guy that has the REST OF THE STORY .. and is not selling anything.
such value is hard to beat..

Click here: VATS BYPASS


This gent is a lock smith .. same principle, different approach. Made a few edits w/o changing the message.

Anyone who has come across a VATS ignition that is working (mechanically), but the wires are broken, contacts failed, key capsule mal-function? solution!

On the spot, you can wire in one of these resistors. Just think, the customers choices are to replace the ignition at about 100.00 in addition of the labor fee. When I get a call from someone who has told me that their ignition is turning but the security light is on, I immediately know the problem is in the contacts in the switch or the wire is broken.

At this point the customer is in for a $275.00 solution with a roaming locksmith. An alternative ?

I have wired in a couple of hundred of these. They act exactly like the resistor in the key. Under the dash where all the wires come down from the column, you will find an orange wire with 2 white wires inside. Simply cut or unplug the wire and wire the appropriateresistor (VATS values 1 -15 .. see chart in next posting) to the end going to the cars Brain.(not the end going up the column). DONE!

To install the resistor (the VATS bypass) I charge $85.00 at my shop and $125-175.00 on location, depending where car is.

Kit includes 10 resistors for each value 1 to 15 per the GM VATS value list.

This item is not for the newcomer. This item is for locksmiths who have some experience with automobiles.


Old 02-13-2008, 06:13 PM
Stealth's Avatar
Super Moderator
Thread Starter
Join Date: Feb 2007
Posts: 3,945
Default RE: GM Cadillac VATS Bypass - Passkey II - code B2711

I understand that the same VATS keys are used on the following Cadillac models - the following info was gathered from sellers of the aftermarket sellers of VATS keys. Going price, out the door from around $18 to $30 for the set.


1———— 0.402 (acceptable range .386-.438)
———— 0.523 (acceptable range .502-.564)
———— 0.681 (acceptable range .650-.728)
————-0.887(acceptable range .850-.942)
————-1.130 (acceptable range 1.085-1.195)
————-1.470(acceptable range 1.411-1.549)
————-1.870(acceptable range 1.795-1.965)
————-2.370(acceptable range 2.275-2.485)
————-3.010 (acceptable range 2.890-3.150)
————3.740(acceptable range 3.590-3.910)
————4.750(acceptable range 4.560-4.960)
————6.040(acceptable range 5.798-6.302)
————7.500(acceptable range 7.200-7.820)
————9.530(acceptable range 9.149-9.931)
————11.801 (acceptable range 11.320-12.290)


VATS stands for Vehicle Anti Theft System. Lots of people refer to this type of key, as a " computer Chip key". This key or "Chip" has nothing to do with a computer, nor is it a chip. The black chip on the blade of the key is actually a resister. GM first started using the Vats key in 1986 on the Corvettes, then the Allante, ECT. GM uses 15 different resistors in their VATS keys.

How does the VATS System work?

Each VATS key has it’s own unique cuts on the key to operate the lock. But the cuts alone will not allow the car to crank. This is called a mechanical key. Each car has a Vats module (Brain) under the dash that communicates to the starter, fuel pump, and the ignition lock.

Each VATS module is randomly given a # (value) from the manufacturer. When the proper mechanical keys, with the proper vats chip (resistor value) turns the ignition lock, the vats module reads the chip on the key. If it is the correct chip, the vats module will tell the starter and the fuel pump to operate. If the wrong chip is read, the vats module will tell starter and the fuel pump to shut down.

How to determine the Value of your key?

By chance you may know what vats key you now have. Most people do not. There are basically two ways to determine what vats key you have. Remember, there are 15 different possibilities. First, your key can be " read " in a vats tester. Most locksmiths have these readers, and don’t charge anything to tell you.

There is a way for you to read the key value yourself. If you have a Volt Meter you can test the OHMS (The Value) of the chip yourself. Just set your Voltmeter to check to 20 K OHMS Take each lead and place it on each side of the " chip " on your key. A number will appear. Take that number on your voltmeter and apply it to the OHMS chart. it may not be exact. Just pick the closest value to your reading.

Old 02-14-2008, 07:57 AM
Stealth's Avatar
Super Moderator
Thread Starter
Join Date: Feb 2007
Posts: 3,945
Default RE: GM Cadillac VATS Bypass - Passkey II - code B2711

I understand that the GM Cadillac cars using the VATS are the folloing:

Cadillac Allante 1989 1990 1991 1992 1993

Cadillac Brougham
1992 1993 1994 1995 1996

Cadillac Concours 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

Cadillac DeVille 1991 1992 1993 1994 1995 1996 1997 1998 1999

Cadillac Eldorado 1989 1990 1991 1992 1993 1994 1995 1996

Cadillac Fleetwood 1992 1993 1994 1995 1996

Cadillac Seville / STS 1989 1990 1991 1992 1993 1994 1995 1996

and almost every other GM car of the same period, including the Corvette that 1st introduced the VATS.

Old 12-15-2009, 10:25 AM
Junior Member
Join Date: Dec 2009
Posts: 1

i cant do all this but i have this problem, can you tell me where i should go to get the problem fixed i live in Fargo ND. if i go to Gateway Chvrolet dealer how much will they charge me.
Old 12-17-2009, 12:21 PM
Senior Member
Join Date: Oct 2007
Location: Tampa, Florida
Posts: 230

When I had my 1992 Allante I thought that the ignition was going bad so I purchased an ignition switch with vats key.I sold my Allante very shorty after buying it, ( along with tons of other stuff) so if you find the need for one let me know.
Old 12-17-2009, 12:28 PM
Senior Member
Join Date: Oct 2007
Location: Tampa, Florida
Posts: 230

sorry double post

Last edited by jono6406; 12-17-2009 at 12:29 PM. Reason: double post had to delete
Old 04-20-2010, 03:45 PM
Junior Member
Join Date: Apr 2010
Posts: 1

Not sure why, but everybody around seem to keep calling "VATS Bypass" a simple resistor to install under your steering column or on the TDM's connector. But the problem with that is it will only bypass the key and the lock cylinder, while the entire core of the security system (the TDM or Theft Deterrent Module or anti-theft module) still remains in the loop!
That resistor trick was born just to add a remote starter or fix a broken wire, but today it makes little sense. Today is the TDM that is causing tons of problems around! It dies systematically with the age of the car - even way before her 10th birthday. That's what happened to my trusty Buick and is happening to other tens of thousands of unfortunate people in North America. Lots of people are even junking their cars since GM discontinued the production of the TDM back in Jan 2009.luke has written an excellent post on this topic, you may see it at http://vatspasskey.com/
Old 09-13-2016, 08:15 AM
Junior Member
Join Date: Sep 2016
Posts: 1

how do you find out which pass key code fits your car if you dont have the key anymore
Old 09-13-2016, 11:21 AM
slowroll's Avatar
Tech Certified Members
Join Date: Oct 2007
Location: in the mitten
Posts: 3,160

should be a new thread. Depending on year most likely mid 90's by now you could bring proof of ownership and ID to GM dealer and see if key codes are still available. Normally blank number is part of it, but not always. Key code would be original by GM not if changed later for some reason. Blank number rarely changes because it is burnt into VATS module on first key cycle. It can't be overwritten. Dealer has a tool to bypass VATS which has the resistance value of all keys. Starting at one and proceeding upwards every three minutes until car starts to reveal blank number. I would have a non vats key made first to be sure it rotates in cylinder before buying more expensive VATS key.
Old 09-27-2017, 10:07 AM
Junior Member
Join Date: Aug 2017
Posts: 2

Hey, does anyone know if an '89 Caddy Fleetwood has VATS or if I need a bypass module for it. I'm about to get a Viper 5706V remote starter/alarm installed but my key doesn't have a chip or lump on the key so I'm not sure. Any help is greatly appreciated. Thanks
Related Topics
Thread Starter
Last Post
General Tech
05-10-2012 01:06 PM
General Tech
07-20-2011 07:32 PM
05-19-2009 03:28 AM
General Tech
12-11-2007 10:57 AM

Thread Tools
Search this Thread
Quick Reply: GM Cadillac VATS Bypass - Passkey II - code B2711

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.