Expert: Rob Painter - 12/21/2011

Question
i have a 97 CADDILAC DEville and the theft system is on i change key lock knew key where programed i change steering column and put knew key switch in it  my question is where would the anti theft box be located

Answer
Hello,

It gets very frustrating for me when the owner tries to fix the car first before seeking out answers first before changing the lock and steering column. You say you have a programmed key for the car. This is not like programming a transponder key. All you are doing is mating the resistor on the key to the VATS module. Very low tech! This is the antiquated problematic piece of garbage that GM held out as anti theft when in fact not one system made by any manufacturer is anti theft and are in fact anti-owner when they fail, or better yet are a great reason for insurance companies denying an auto theft claim, because they have purported self-proclaimed forensic shill hacks that will say these cars are unstealable.

Let's get down to your car. You have a GM VATS (Vehicle Anti Theft System) also known as Pass Key. First used in 1986 on the Corvette in 1966 and last used in the Corvette in I believe 2005.
There is no programming like one woul do with a hand held electronic programmer like that used for transponders. The chip in the key blade is not a computer chip like cops commonly called it, but merely a resistor. The system was changed in 1992 to the Pass Key 2 which no longer had a choice of 15 resistors and was now 14 different values.

To obtain the proper resistor key and have it cut, all one needed to do was give the 17 didgit VIN behind the windshield to a dealer and the dealer could supply not only the correct resistor, but cut the key as well to give anyone a working key. The forensic goofs would go into a schpiel about how the person obtaining a key would have to prove ownership with a secret hand shake or something, but the truth of the matter is this was b.s.. I know that because I obtained many just to show how easy it was for court. Real good anti theft system huh?

In order to use the "interrogator" to determine what value resistor was required, there was 4 minutes between tries. This was stated as fact. That is because the locksmiths and forensic experts were too inept to realize that the interrogator had a 4 minute timer between resistor attempts which was built into the machine. If a thief or I went between resistor attempts, it was actually only 2 minutes, but that goes back to the ignorance of these people that believed what they were trained to do.

Since the VATS use spanned 19 years, from an electronics stand point, this system was ineffective against theft after 2 years and that was from the 80's perspective, but GM kept putting this junk in their cars for 19 years.

GM, Ford, Chryslers did not manufacture locks and keys. This was sub contracted to Strattec of Milwaukee, a division of Briggs and Stratton. Since I was located in Milwaukee and I had access to the plant, I spent a number of years watching all the operations required to make locks and keys from raw stock. This is something far more than a locksmith ever had the opportunity to do. I was not there to steal trade secrets and I wouldn't o that any way. My purpose was to know more about the manufacture of locks and keys than anyone in my industry and as you see, I do know more than anyone else.

If you obtained your key and lock from the middle man dealer, you were seriously ripped off! Locksmiths and parts stores obtained the lock and keys from Strattec as well.

Besides, whatever you paid for the lock and harness assembly was too much!

First of all, why would you change the lock cylinder, then put a use column in the car and then put the new lock cylinder in again? I don't understand why you ever went to that much work for something that is doomed to fail?

First, you need to establish if this is a VATS problem in the first place. The anti theft systems are blame first for something that may not be related. Is there power at the starter when ignition is put in start position? If there is, the starter is junk and will give the same symptom of not cranking.

The problem here is that you now may not even know where you are at with all this part changing. Please o not misunderstand, I am not criticizing you. I am the same way. I put things together without reading instructions and get upset when there is a problem. I am a guy and that is what most of us guys do.

If you know for a fact, the correct resistor is being used an it isn't a starter problem or electrical ignition switch problem (located under dash on top of steering column towards the firewall (Will give you same symptom of no crank too), however it would be hard to believe you have two columns with a bad ignition switch. You could have a bad module (very, very rare-in over 10,000 repaired theft recoveries have only had 2 bad modules), it should be located behind the glove box. The reason I say "should", is that I no longer remember the specifics on your make and model. This was the most common location I remember. It could also be a bad BCM (Body Control module-vehicle's computer).
Before fighting yourself any more, there are 2 things that you need to do. You need an electrical service manual for this car. I think it is too old, but check to see if you can download one for $30 at http://www.alldata.com, or try a library or see if you can obtain one through Ebay or Craigs. The factory service manual will give you a diagnostic flow chart to keep you from changing perfectly good parts and will tell you the location of everything you need to find.


See, when you start changing parts, you could be changing with unknown failed components.

Here is another thought. Are you absolutely sure that you are not dealing with a system once bypassed in which the bypass didn't fall apart?

VATS is notorious for failure in which the very thin white wires leading up an down the column break inside the plastic insulation. You would never see the broken wire and you might not even find the broken wire with an ohm meter because once you move the harness around, it may temporarily go back together. I highly recommend this bypass because the computer sees the correct key being used every time. This bypass could be applied any where in the vehicle to that harness. all it is, is putting the correct resistor in line. If bypassed and came apart wherever bypassed, no matter what you change, this engine is not starting until that issue is repaired!

The best advice I can give you is quit the guessing and get a factory manual for the car, besides you will find it handy in the future for other repairs as well.
For an anti theft system they are very, very low tech, but they can be a real pain to trouble shoot.

If you do change out the VATS module, your "programmed" key is no longer any good if obtaining from a junkyard. You need the key that matches that module. New VATS modules are north of $150.00 and your key will work, because it recognizes the first resistor burnt into it. If you can no longer get a new one from a dealer for a 1997 Caddy, all you need to do is get a new one for a 2000 up to 2005 Vette. Same module. In fact, if you are just trying to fix only the VATS,  you can get a downloaded service manual for say a 2004 Vette at http://www.alldata.com and that will give you the diagnostic flow charts you need to fix your Caddy. Same junk system, same wiring, but more available service manual for the VATS.

Good luck. Let me know how it turns out.

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