John in RI

iTrader: (167)

I've got a VATS module that was probed to find the OHMS. ( PINS 'A6' and B2' on the Module. ) I got 15.20 (15200) when it was checked. The factory VATS resistor range of the VATs key type 15 is 11328 - to - 12292.

I was looking into a VATs module for another member and after finding him a good one I checked a different key/module ( from the same car ) I had stashed away on an 89 cloumn. Once I saw that modules' resistance was @ 15.20 I realized there was no key for that value. So; I checked E-bay and found a seller that was selling these modules,..... and several of them had 14.0 or higher resistance.

Question; Is this VATS module ( 15.20 OHMs) still any good ??


My guess is that it probably can't be used with an original VATs key again and the only way it MIGHT work is if a resistor chain was used to bypass the VATs key.


THANX in advance !

Tuned Performance

iTrader: (92)

Not sure the key value for the module is. He could use these to find out the keys value. Then have the new value pellet key cut.

https://m.ebay.com/itm/The-Install-B...ss!92617!US!-1

Drew

iTrader: (58)

Not sure I'd recommend this process... You'll get 17? resistors tossed in a mini ziplock bag. None of them will be dead on, two will fall in the range for #14, and two will be outside of the published ranges. Haven't tried to use any of them yet, but knowing which value I'm shooting for, I have a fighting chance of making them work. But I think if I were ordering a set again, I'd try a different seller.

Are you saying you can read the VATS module with a DVOM to get the matching key value? The only way I've ever heard to get that from the module was to have the Lock Exorcist (smith) hook up the... "VATS INTERROGATOR"

John in RI

iTrader: (167)

I assumed a LOT of things here and I'm most likely WAY OFF. A better question would have been "How do I test a VATs module".

When I saw that the OHMs were listed in the web listing I assumed that he had a way to check them & was probing the module in the locations that I described. (Module A2 and B6 PINS ) These are the 2 pins that lead to the ignition 2-PIN connector at the base of the column: HIGH and LOW reference circuits to/from ignition.

I don't have a VATs car or a full VATS system to work and I'm just not that familiar with it, so once I saw a chart with the key values on it I grew more confused due to the resistor range @ Key 15. Never thought about the # resistors it would take to reach 15.20 either - another clue that I was going about it all wrong !

Drew

iTrader: (58)

I would assume that you could mock up a VATS module circuit on the bench. Power, power, and power in, ground, ignore the ECM fuel enable out, hook up resistor #2, turn on the power, and watch to see if the start enable relay output grounds. If it fails, power off, wait, hook up resistor #3, try again... Repeat until the starter enable grounds, and you've got the resistance of the matching key. I'd expect you'd need an oscilloscope or something similar to tell if the fuel enable output is correct.

Unfortunately, from what I've seen, the key/module need to stay matched, and if the key gets lost, the only way to recover the value is to try every key value until the module responds. Just the idea of trying 15 values, and the wait between failures, is enough to make me consider that a VATS module without the matching key is probably not worth messing with.

I'm curious if there's another way to find the resistance, or test the module. Part of me wonders how the new, blank module, can burn itself to the value of an existing key on the first power-up. That's what they say it does, but you would think there would have to be a way to wipe the memory and start over... But IDK.

John in RI

iTrader: (167)

I was hoping to avoid mocking it up,... simply because I don't have all the parts and would have to make stuff to get it to work right. ( so much quicker and easier when you can just plug it in and go ! ) Good advise,... though about just hooking up a bulb to the "SECURITY" wiring, but a full check including the fuel enable and starter relay is far better.

Lurbie

iTrader: (3)

I'm pretty certain you can't measure anything inside of the module to determine what VATS key to use. A new module records the first resistance value it "sees" and that module is married to that value for life. Not saying there isn't a way to reset it, but I don't know what that would be as it wasn't designed to be reset by the public. Using the VATS Interrogator should take no more than 1 hour, but as you said you'd have to have it all hooked up to the car to fully and quickly test. Once the proper key resistance value is identified by the VATS module, it enables a ground path to the starter and sends a frequency signal to the ECM to enable injector pulse. It's been over 20 years since I've messed with them, but IIRC that fuel enable signal was 50Hz.

Drew

iTrader: (58)

Mocking up the VATS system on the bench wouldn't be too crazy difficult. The wiring diagram is almost entirely grounds and power. The only part that couldn't be verified with a test light is the fuel enable output.

I've fortunately never had a VATS issue that couldn't be resolved with a fresh key-blank, but I can completely understand why so many people bypass the system.

Tuned Performance

iTrader: (92)

The injector hz output is 2.5v or 30-50hz at 50-60%. I think the member who needs this is just concerned about the enable relay grounding. Post 3 , I think drew posted a better image in another post.
https://www.thirdgen.org/forums/elec...ent-relay.html
I was thinking of Post 5 but it doesn’t show the passkey module
https://www.thirdgen.org/forums/elec...questions.html

Drew

iTrader: (58)

I have a better picture of VATS module interrogation...



One note about the pics in those two threads.... The VATS start enable relay changed in late 91 or 92. Before the change, the VATS relay is wide and flat, kind of like earlier thirdgen relays you'd see under the hood. After they used a more traditional square relay. One of each style is shown in the pics in those two threads.

John in RI

iTrader: (167)

Drew - That's Funny !!


Brian; A BIG Thanx for keeping me in mind !

& Thanx for the info shared by all others too. Things have been "weird" here lately for the me and with so much on my mind I just didn't think this thru as well as I normally would have before I started making assumptions & probing stuff.

At some point I'm sure I'll bet the itch to mock-up a way to test it as best I can. I'll buy one of the resistor packs described in an earlier post above and will get it figured out at some point in the future.

canadamaro

You can reach the plug on the module without removed the dash (on a 88 GTA at least). Mine died at work so I just plugged in a new one (I had to do the resistor bypass thing) in order to be able to drive it home to fix it. Sadly almost 2 years later I'm still driving around with 2 modules in my car but it works.

jlarsson

iTrader: (5)

Here's how to test a module, just did this myself ... you should not use anything to measure the resistance of the module as it's solid state ....

https://www.thirdgen.org/forums/elec...ml#post6402078