I know the exact problem with my car. and I've read through
some previous posts on the issue. I havn't been able to find
any other solutions other than the resistor replacement.

It's a simple, common, and extremly annoying problem. The
VATS module is not correctly decoding my keys resistance value
of 4-8K Ohms;

Thus, it's preventing the car from starting. Now I am assuming
that this is the PASSKEY-I system. It's a 91 Camaro Z28 305 TPI
automatic; When I turn the key, even if the security light stays
on and the car won't start; I _can_ hear a short "groaning" noise
that sounds much like the fuel pump test proceeding. If I'm wrong
stop me here.


I've heard of people grounding out the starter relay to allow the
car to turn over; now since I can hear the fuel pump run; I'm
assuming that if this trick was preformed and I was to attempt
to start the car, it would continue to run. and run and run..

What I need to know is what wires to ground out, where they
are located. and if I can use an on/off switch mounted on the
passenger side of the tranny gear selector that I could turn to
On to enable the starter, start the car, then flip it off.

(and expect the car to still run)

What i'm looking for is a kill/enable switch in one that would allow
me to start the car; instead of shelling out $300 for a new ignition
(which i've already had to do once before, three years ago) and
something I could turn off to prevent a start like a kill switch.

basically, would using a starter relay bypass allow this car to start
and run normally; I need some feedback. I havn't been able to
dig up any solid information on this.

Thanks

 

If the problem is VATS, what you are proposing will NOT let the car start. It will only let the car CRANK.

VATS controls 2 things on the car.

1) The starter enable relay, which you are trying to bypass.

2) The fuel injector pulses thru the ECM.

Number 1 is easy to bypass; number 2 is not as easy. After you bypass the starter relay you could add an aftermarket VATS bypass module to send the correct signal to the ECM, or have the PROM inside the ECM reprogrammed to turn VATS off.

The fuel pump relay has nothing to do with VATS.

 

You sure about that? I taped a piece of tape over my key pellet and the gauge (temp I think, not sure about that. Away from home) moves to the extreme like it is going to start but you don't hear the starter crank or anything other than the fuel pump pressurizing the car. At least that is the way it is with my 91 Firebird

 

Am I sure about what?

If he bypasses the starter enable relay, then yes, that will allow the starter motor to crank the engine when the key is turned to the crank position. It still won't start, but it will crank.

If you bypass BOTH parts of VATS, then it will do both, crank and start.

All you did was trick the system into thinking the incorrect key was inserted. It sounds like it responded properly. It didn't crank OR start. That's the way it works on all of these cars.

I don't follow what your point is?

He was thinking that since he hears the fuel pump run, that if he can make the starter engage, the engine should run. I'm explaining that the fuel pump has nothing to do with VATS; it's the combination of starter enable relay and fuel injector pulses that make up the VATS system. You have to get around BOTH before the car will actually RUN.

John

 

I'm sorry. I require a second opinion.


The system you are describing is the PASSKEY-II system; I am
not sure that this is the system this car is using. I believe it to be
the PASSKEY-I system.

Reason? The previous owner of the car experienced the same
issue, the car would not crank; the security light stayed on
at every attempt. Her solution? she crawled under it; and with
a screw driver. crossed the posts on the starter, starter cranked
the engine; car fired up -and- ran like it had no problems.

This tells me it's the PASSKEY-I system.

Back to my previous question.


now a few things to note; between now and then we have not
done an ignition cylinder swap. it's the same ignition switch,
the starter was swapped out because of a shot bendex, but is
the same brand.

Now, let's assume that the security light was not on during these
times that she could not get the car to start by the old fashioned
turn-key method. That would suggest that the entire lock cylinder
may be faulty; however I pose this question: their are two parts
to that moving equation. it is already random enough to attempt
to get the VATS to detect the key properly, assuming the ignition
was shot as a whole (being the 12V cross to starter post in the
cylinder) it would again be random. so you've got two completly
random possabilities that you would have to match completly
in order to get the car to start on any given day.

considering, on any given day, and giving a maximum of 30
minutes; I can start this car with no under-the-hood fiddling, we
must assume that the 12V post to starter post in the lock cylinder
is indeed good. and the only failing part of the cylinder is the VATS
key detection contacts.

This, in turn; is also backed up by the fact that when she turned
the key in the ignition; power was lost to all componets, and the
in-car tempature gauge pegged to 260 proving that 12V did make
it to the starter relay.


So this only leads us to believe that; because the fact you can
get the starter to start the car by crossing the posts even with
the security light on, and an attempted start from within the car
with the security light on does not give the resulting 'click' from
the starter; as well as the fuel pump being primed even if
the security light is on. This only directs me to believe that this
is the PASSKEY-I system. which does _not_ disable the fuel
injector pulse sequence if the incorrect resistance is detected
in the key.

It only disables the starter relay.

 

Well, I won't pretend to be at your elevated level of knowledge of how these things work. I was only a GM electrical systems engineer for 23 years.

If you can short the starter solenoid and the engine runs, it's not a VATS issue (unless the memcal had been modified). It's something in the starter circuit, possibly a faulty starter enable relay.

One bit of advice from a guy that doesn't know much about these things; buy a factory service manual for your car and READ it. You'll quickly see that 75% of your statements and assumptions are INCORRECT.

Good luck.

 

I'm not pretending to be at an elevated level knowledge about these things. I am telling you what I have observed and what
I have read.


I'm not going to fight with you. This is a waste of time.

However, I am asking for a second opinion. I do know their are
two PASSKEY systems, version I and II; both offer completly
different levels of protection.

Your opinion has thus far been one sided; considering that
you shouldn't be able to start the car by crossing posts if the
resistance isn't detected correctly; in a PASSKEY-II protected
car.

Tell me more about PASSKEY-I oh great wise one.

 

Oh, BTW; the ECM has been replaced.

and the alarm system was aftermarket; then later most of it
was disabled by the previous owner's boyfriend.

It's still connected, it just doesn't exactly work.

 

With that most recent bit of information I'd say it's more likely that you have a malfunctioning alarm than a VATS issue. Many alarms have a starter kill relay which is normally open and only closes when the alarm sends it a ground signal. Trace out the remnants of this "not exactly working" alarm and I'll bet you will find your problem.

 

If the Security Light is on all the time, VATS isn't working.
you could even have a bad neutral safety swtich on the car.

Best way to wire up the car so that it won't run is to hide a switch for the ECM Ignition power. With no power to the ECM, fuel pump won't prime or turn on and the injectors won't fire.
I found this out when I forgot to hook up that wire when I did my carb to TPI swap. One whole day wondering why my pump and injectors wouldn't do anything. My car would crank over since I have an 86 and I removed the VATS from the the 91 TPI prom.

Speartech, one of my friends ordered an LT1/4L60E from you guys about a week ago. hopefully the motor arrives soon and we get it installed and ready to go by the 28th of this month, trying to make it to SLP Day in Orlando.
We are going to find out where to place the ECM today and let you know how long to make the ecm wires.

 

How do you bypass the VATS on the eprom? My friend wants to switch from an 88 tbi computer to the 8746, which has VATS and his car does not. I see there are two values for VATS on the bin, and they're both set to 255, would changing them to zero remove all vats functions, or would we have to do that (or change them to a different value?) and ground out the starter?

 

Zepher: That's a fairly tight schedule to meet when you consider the truck freight time and everything else, but I do have the guys working on his package. Hopefully we can pull it all together quickly!

John

 

Chuck!: VATS in the eprom on PASSKEY I? How can that be? lol

Yes, if you set it to 00 at hex location C007, that will disable the injector turn off. I'm not aware of a 2nd location?

If the car didn't have VATS anyway, then nothing needs to be changed starter-wise.

 

Ok, Ill give it a try. Im just getting into the computer stuffs here so Im pretty shaky about doing it all. Thanks for the help!

 

That would be awesome. We appreciate it.

Oh, and I use TunerCat to program my chips and there is a VATS setting that you can check or uncheck.
http://www.transamws6.com/pics/transam/cats.jpg