oletrucks
[Top] [All Lists]

Re: [oletrucks] Ignition key

To: J Forbes <jforb@mindspring.com>
Subject: Re: [oletrucks] Ignition key
From: Robert Baird <bairdr@charter.net>
Date: Wed, 19 May 2004 19:13:22 -0500
I do I do!!!!!!!!!!!!  I Have some 555ic in sm
Robert

J Forbes wrote:

>> Here is a question for all of you electronic gurus on the list:  I 
>> have removed the steering
>> column from a 1993 Buick LeSabre and plan on installing it in my 54 
>> 3100.  I will also install
>> a 1985 TPI 305.  Can the 1985 ECM be programmed to take advantage of 
>> the "chip" in the key
>> on the column for security?  Is this more trouble than it is worth?  
>> I plan on using this as
>> a daily driver and would like to be as secure as possible.
>
>
> I'm not sure how the Buick system works, but I have some experience 
> with the 90-92 F body VATS setup.  The chip in the key is just a 
> resistor.  The value of the resistor varies, so you have to have the 
> correct resistance to activate the system.  But it works in a strange 
> way...the resistor is used in an oscilator circuit in the VATS module, 
> which puts out a square wave with a frequency that depends on the key 
> used.  If the correct key is used, the signal is at 30 Hertz, and the 
> engine computer will accept this as a "good" signal and keep the 
> engine running. If the wrong key is used, or no key is used, the 
> signal will be "bad" and the engine will stop after a few seconds 
> (injectors shut off).
>
> So...if the 85 ECM does not have the VATS feature, then no, it won't 
> work.  But you migth be able to use a newer speed density computer 
> (1227730) with the appropriate prom and wiring (and VATS module) and 
> make it work.  The folks who reprogram ECM proms can disable the VATS 
> input, so the car will run with no VATS signal.  A cheap fix is to 
> make your own square wave generator using a few cheap electronics part 
> (NE555 timer) and make your own VATS module, which can use no key or 
> whatever key you want.
>
> Survey:  who understood what I just said?

oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959





<Prev in Thread] Current Thread [Next in Thread>