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4.9 VATS Bypass problems

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orange View Drop Down
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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Topic: 4.9 VATS Bypass problems
    Posted: 25 September 2010 at 4:34pm
It fires for a couple seconds but then nothing, almost sure
it is the passkey bupass, the one i have i came with the
harness when i bought it so im assuming it works. is there
a way i can test it? Also the bypass i have was home made
and i think they built in the vss speedo converter in the
same module to save space or something, the module has
black and red and blue wires, but then also a green and
yellow (vss is my guess) or are these wires for the bypass
and im missing something? Almost sure the computer is a
1991 and i think those were 30hz? Advice appreciated.
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Post Options Post Options   Quote Dr.Fiero Quote  Post ReplyReply Direct Link To This Post Posted: 25 September 2010 at 9:10pm
You didn't just bypass it in the PROM?  Way easier.

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 26 September 2010 at 1:21am
Originally posted by Dr.Fiero Dr.Fiero wrote:

You didn't just bypass it in the PROM? 
Way easier.


PROM? I have a Rockcrawl chip, and a bypass. Could they be
canceling eachother out if the chip already has it
programed?
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 26 September 2010 at 7:43pm
They can't really cancel each other out.

But, if you search VATS, I think you'll find that there was 6 or 8 different resistances they used on the key plugs.

If your ecm expects to see one value, and the 'bypass' is inserting another value they may not want to work together.

Did this combination ever work?

That best way is to get someone to burn you a new chip with the VATS disabled. It's just a enable in the bin file. Rockcrawl should be able to do it; they must already have the bin and the hack if they've provided the chip in the first place.


Is the ecm a 1227730?

Chay
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 26 September 2010 at 7:52pm
Ok, there were actually 15 values:

http://tpiparts.net/vehicle_anti_theft_system__vats_/

Check the above link.

So, you can find the right R value and hope your VATS module is working right, or you can simulate the VATS module output signal. I don't know what it is, but likely it's either +5V, or ground.

Chay


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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 26 September 2010 at 8:00pm
More good info:

http://www.thirdgen.org/vats_passkey_system

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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 26 September 2010 at 8:03pm
The input is a square wave from the VATS to the ecm. The simple solution is the resistor to the input of the VATS.

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 28 September 2010 at 5:46pm
Thanks for the info, and i dont really know what my
computer is. But is there some way i could test the bypass
signal, and could i take a frequency generator and hook it
up just to make sure that is the problem? Or would the
round waves from a frequency generator not be sufficient
for the square wave needed?
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 8:18am

I think you'd need a square wave gen. Most gens which will do a sine wave will do a square wave.

 

The trick is to determine the frequency and amplitude. I have no idea what they are.

 

If someone was willing, you could 'scope a working unit, then build a f gen to match it (555 timer) and you're set.

 

Chay

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 4:54pm
My ECM is 16132240, which frequency would it be, i got a
frequency generator to test. I tested the Bypass module and
it seems to be putting a 50Hz frequency out.
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Post Options Post Options   Quote Dr.Fiero Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 4:56pm
That sounds right (mind you it's been quite a while).

If you've got it disabled in the PROM - this is all a moot point anyhow!  The ECM isn't even looking for the signal.

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 5:43pm
What is PROM? And the injectors turn off within 2 seconds
so i dont thing i have it disabled in the PROM
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Post Options Post Options   Quote Dr.Fiero Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 6:13pm
PROM - Programmable Read Only Memory.
("the chip")

I'd be really surprised if Rockcrawl didn't disable it...  but you never know...

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 29 September 2010 at 7:45pm
Well the injectors do turn off after 2 seconds and the
computer and harness came with a Bypass module, so im
assuming the PROM doesnt have it disable. But im so
confused right now its ridiculous, PLEASE help me trouble
shoot this, i need this project done!
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 30 September 2010 at 9:09am

It's 50hz, but how big is it (What voltage)?

Anyway, if the 50hz output is working at all, I believe it means the VATS module is working. Do the resistor thing on the input, simulating a key.

It's the wihte/black, purple/white:

 

 

 

 

 

This is the only wiring diagram I can find. Take it with a grain of salt; I don't know what car it's for.

 

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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 30 September 2010 at 9:11am

 

Looks like it diables the starter too....does your engine crank?

 

If so, maybe it's not the vats!

Ok, check that, who knows how your engine has been wired. I'd definatley trace some wires here though!

Chay

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 30 September 2010 at 6:16pm
I am more confused now, sorry. I dont have a vats module, i
just have the ecm and the bypass module hooked to power,
ground, and F 10, the vats fuel cutoff. Yes my engine will
crank over and all 8 cylinders will fire once maybe twice,
then nothing. The injectors ARE being cut after 2 seconds.
My bypass is putting out 50Hz, i know thins for a fact.
What voltage should it be producing? 5V or 12V? Thanks so
much for you time everyone!
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2010 at 8:47am

Ok, now we're getting somewhere.

Look at the circuitry at the top right of what I posted. The ECM provides the power, at 5 volts.

The vats module switches it to ground, causing the signal to go to 0 volts.

 

So, you should have a square wave, from 5 to 0 volts.

It's funny that the diagram above doesn't show the switch being pulsed.

 

http://myplace.frontier.com/~vze7erz1/id14.html

 

Looks like they used more than 1 frequency. Perhaps you are supposed to be at 30hz?

 

A diy cct for 50hz, you could modify it for 30hz. Let me know and I can build one and confirm values.

 

Chay

http://home.hiwaay.net/~davida1/passkey.htm

 

 

 

Chay

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Post Options Post Options   Quote orange Quote  Post ReplyReply Direct Link To This Post Posted: 01 October 2010 at 4:38pm
Ok so I hooked the positive feed of the bypass module to
the 5v reference thinking that would work... it didnt. I am
extremely frustrated, and am ready to just buy a whole new
module and eliminate this as my starting problem.
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Post Options Post Options   Quote CFoss Quote  Post ReplyReply Direct Link To This Post Posted: 04 October 2010 at 8:48am

I can see that time is becoming an issue for you.

 

Don't get too frustrated. It sounds like you are on the edge of success!

 

What you should do is come and coach my 8 year old soccer team. Then you'll know what frustration is! Ha. Actually they were really good the other day.

Do you have a frequency generator available to you? You mentioned it before. If so, try the 30hz frequency. Set the F generator for 5V peaks, and 0 volt lows. It should sink current as well as source it, so no problem.

 

I may have time to whip up a variable oscillator and send it to you. You could set the F with a 'scope or a meter.

 

It sure would be nice to verify the VATS is still on in your chip, otherwise you are wasting your time with the VATS. Can you/have you tried contacting rockcrawl?

 

Chay

 

It would be great if you had access to a 'scope so you could see it happening.

 

Chay

 

 

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