GIJoe

Well, I had the VATS programmed out of my new PCM chip I just got.
I have also previously done the resistor bypass in the lock column.

Today, VATS is back! I came out from work and it wouldn't start. I waited a few mins, still no go. I waited 6 mins this time, then it cranked right up with no problems.


Question (and yes I searched high and low for an hour on the forum here and an additional hour on Google)... What else do I need to remove? I want this POS system GONE FOREVER! ARRRGGG!!
Aren't there some wires I can clip to wire things straight into the computer, bypassing all the vats modules? Can I somehow have the FI and Starter systems just wired up so they don't go through any VATS crap anymore?

I have a feeling that one of the modules is going/gone bad and is still causing problems for me even though the PCM is bypassed and the lock column is bypassed.

I saw a diagram up for the entire system a few months back, but that was for the late C4's. Does anyone have some better advice or tips for an 89?

ALL help is GREATLY appreciated.

A car I can't trust to start is absolutely useless.

GIJoe

I forgot about my AllDataPro DVD set and decided to look around in there...

http://joestradingpost.com/pix/vats/

Those two diagrams are what came up for Anti Theft. The 1st one (smaller diagram) is for "passkey" the 2nd larger diagram is for "alarm"

Is all that part of VATS, or is there more to it? I am trying to figure out how I can remove this entire mess.

From the 1st smaller diagram for "passkey" , I am curious if the "solid state detector and timer" module is what is bad at this point. But I don't understand why the PCM bypass isn't stopping all this from happening?



BTW, I can create higher res clear images if anyone needs a better look at this.

I can also provide full sized images for anything else you all need too
I have pretty much everything from 83-03 imports and domestic (i am only missing a few makes)

redrose

the starter (crank enable) relay can be bypassed by connecting the wires that carry power to the starter solenoid together at the relay...mine (86) has two yellow wires, verify yours...one of those trailer wiring connectors with a slight mod so both wires run thru the connector is quick.
the other vats function is ''fuel'' enable (injectors)...need a 30 Hz sink of the ecm 5v output to get the ecm to fire the injectors...you can buy a 30 Hz sink from several vendors on the net for $30 and up, or if you have rudimentary electronics repair skills you can build your own for abt $10 using a 555 ic (send a SASE for a copy of my ''experimental'' schematic)...three wires from the sink tie into power, ground, and the ecm signal ,at the ecm---vats is just a memory!!

CorvAdel

Hey Joe...my stuff arrived today!..It is all there as agreed. So, thanx for that.
Re. your vats. I can only tell you about my 86 vats issue.
My module was faulty. I needed a chip tune. I mail ordered one and had vats, with other stuff, removed.
My car still wouldn't start.
After playing around with it, I found the only way to start it was to ground the green wire from the vats, which goes to the st. enable relay.
I rigged up a "secret" spot for a button, which needs to be pressed while cranking. This provides the ground and the car starts....EVERY time.
I have no vats issues now, but still have an effective theft deterrent mechanism...!
I just love this set-up....may be it can work for you too...?

VQT88Vette

Who program the VATS out of you PCM and what is the PCM?
I know that "tjwong" a forum member will reprogram the e-prom to take the VATS function out but you still have to short the starter relay in the middle of the dash.
I have the same problem but don't have the time to take the dash out yet (maybe too lazy lately) to short the relay.
PM tjwong for more info.

tgtexas02

GI, I may be way off base here but as I read my diagrams, I don't see where the ECM really has anything to do with the cranking aspects of VATS. I am actually going through this right now too. But, I want the VATS to work correctly! I will recheck things tomorrow but this is off top of my head:

Ignition Switch Connector--yellow ("sol" pole hot in start) to center panel starter relay "A" and "B".

DECODER (in RH panel)--Cavity "S" and "T" brown and yellow from column KEY harness. RED power wire from VATS fuse but I don't remember cavity (R or P or?). A BLACK is ground. And, "U" is a GREEN to the center panel starter relay. Essentially, decoder checks resistance from key (S and T). If correct, then "U" carries signal to center panel starter relay cavity "D".

STARTER RELAY (center panel)--"A yellow SOL, B yellowSol, C is blank, D green from U at decoder and "E" is grn/whit to neutral safety and on to bulkhead connector and then to starter solenoid.

Two actions ocurr at key start position, ignition switch power goes to center relay and decoder recieves power from VATS fuse and checks resistance from KEY. All working okay, starter works. I need to check yet but power also goes to the center panel fuse "CINJ" but I don't think it is VATS affected by KEY resistance. Will get back to you tomorrow. Like I said, I am currently going through this same issue. In my case, think my clutch neutral safety switch is bad. Just out of ignorance, if yours is an automatic, is the neutral safety switch properly addjusted?

GIJoe

I was told it must be programmed out of the PCM before you can remove anything in the system itself.


mine is a manual. The neutral safety never worked since day 1 when I bought it. I believe it may have been disabled long ago with some aftermarket alarm install. I was working under the dash one day and found a complete alpine alarm system shoved under the drivers side with lots of spliced wires. I carefully removed the ENTIRE thing and put all the wires back to where they belonged. it was a PITA because the people that installed it cut all the short wires without extending anything. ...I am only assuming they disabled it whenever this was installed (it was like that before I bought the car).

GIJoe

pcmforless. they did an awesome job on the tune too

tgtexas02

I haven't checked my books yet but read your post. My thought is this: once current leaves the relay on the large green/wht wire it is travelling to the neutral safety switech connector. So, when you go to start, DO YOU GET 12 VOLTS AT THE NEUTRAL SAFETY CONNECTOR? If you do, then that is a very positive thing. Maybe just a jumper on the connector at the neutral switch and then it should crank. If it doesn't, then the issue is between the firewall connector and the starter solenoid. I can check on which pin connector the bulkhead uses but I don't remember now. It is a purple wire to the solenoid I think. Can get back later.

redrose

my vats sim

btw, the schematic is available to any CF member, just send a SASE or two first class stamps + your add and i'll provide the return envelope....i call it ''experimental'', use at your own risk...i did a 100 hr power up test with no prob.

GIJoe

What exactly does your "vats sim" do? I want this thing completely disabled once and for all...

GIJoe

it's not the neutral switch. i can still wait VATS out for 5-10 mins and still crank it without pushing the clutch in.

I think its one of the modules that is between the starter and FI system that is causing the issue.

Thanks everyone so far for all the advice. I am going to start looking into some of the wiring, and bypass advice some of you gave me this weekend

keep the ideas coming!

if i can get this all to work, I will make a good writeup of it with pics/diagrams for everyone to use.

redrose

your ign key has a resistor ''pellet'' which is checked by a stand-alone little black box, the ''vats module''....if the pellet is correct, the vats module does two things; it (1) trips the relay to close the signal circuit to the starter, and (2) generates a 30 Hz sink....the ecm outputs a 5v signal which must go to sink (ground) at 30 Hz (a full time ground will not work on any that i have tried) before the ecm will trigger the fuel injectors.
you can discard the ign key pellet, the vats ''little black'' and all associated wiring, if you jumper the starter relay AND install a ''vats simulator'' (sim)
a ''hidden'' toggle switch that interrupts the 12v feed to the vats sim will prevent unauthorized flight....to really confuse ''would-be's'' use a dpdt toggle switch--one circuit in the switch for power to the vats sim and the other switch circuit takes fused fuel pump power to ground (attempting to start with the switch in wrong position will blow the fuel pump fuse, then flipping the switch will still not run)

GIJoe

That makes some sense to me. I like the idea of it all being bypassed, this seems like something I wouldn't mind trying actually. I'll send you a PM for your addy. Perhaps I can create it into a PDF or something so you won't have to use snail mail anymore for future requests

redrose

''scanner'' is on my christmass list...but coal might not be so bad either.

VQT88Vette

ttt

lallend

Curious, have you contacted pcmforless about your VATS problems?

88sk

just went thru the hoops on this1 as well, car sat for 6 months,till today,key tumbler went bad,then water got into tankfrom clogged drain around filler ,the rubber thing acted like a swimming pool& the car wouldnt start, still thought it was vats brain then just got a 30 hz thing which I dont need now,all along bad switch& watered gas,finally it runs.

redrose

congrats on getting it going...always a warm fuzzy when you win

not to pick nits, its 30 Hz not mHz...(big confuse to anybody doing their own design)

Ray Quayle

Joe, This has been covered countless times, but it never hurts to dig it back up now and again. First off in your car VATS is a totally seperate system from the theft Deterrant System that sounds the horns when a door or hatch is opened without disarming once it is armed. With that fact out of the way we move on to your VATS tale of woe. Your car has a VATS Module tucked up behind the passenger side "breadloaf". This module basically has two outputs on one input. The input is from the Ignition Cylinder. It has contacts that connect to your key "pellet" resistor. Wiring then routes this resistance to the VATS Module. If the VATS Module is satisfied the resistance is correct, it enables the two outputs. The main problem as many have said is with the Ignition Cylinder and the early Keys. The contacts in the Ignition Cylinder and Key pellet wore away quickly. The fix was in GM TSB (Technical Service Bulletin) 88-292. This included the part number of the new and improved Ignition Cylinder and Keys. It has also been noted over the years that the wiring from the Ignition Cylinder to the connector under the driver side hush panel becomes brittle and intermittant. All these things lead to an unreliable input to the VATS Module. The first thing you did was to install a "bypass" at the connector under the driver side hush panel. I quote bypass, because the store bought ones are marketed as VATS Bypasses and they don't bypass VATS (as you've learned), but only bypass the Key, Ignition Cylinder and wiring to the connector. Most VATS problems are solved here.

Now lets move on to VATS Module outputs. The first I'll talk about as it was the next thing you bypassed is the Cranking Fuel Enable to the ECM. It is ECM on your car by the way not PCM. PCM (Powertrain Control Module) was a term the automotive industry came up with when the computer controlled auto transmissions like in the 700R4E that started in 1994, I believe. This output is the 30Hz signal that tells the ECM that VATS is happy and it's OK to pulse the injectors. This is what gets bypassed with a tune if a VATS elimination is requested. This is what Alvin would have done to your PROM. In this case the ECM ignores the Cranking Fuel Enable at pin B6 and enables fuel at all times. This is the bit that Andy (redrose) has developed for folks that want to completely eliminate VATS but don't want the expense of a new tune if they don't already need one for other mods. You don't need this as Alvin has done it for you in software (firmware). The other output, that Andy (redrose) also mentioned, but you've yet to do and is the last step on your complete VATS elimination project, is the Starter Enable output. This is a ground the VATS Module sends to the Start Enable Relay behind the DIC (Driver Information Center). With this VATS Module output malfunctioning, your starter won't crank even though the ECM will be pulsing the injectors. In the case of your manual with Alvin's VATS eliminated tune, you could push start your car when VATS is acting up on you. But you want to get rid of it completely, so do as Andy (redrose) said. Get to the the Start Enable Relay behind the DIC. You then have two choices. Connect the Dark Green wire to ground leaving the Relay in place or remove the relay and jumper the Yellow cavity to the Dark Green with White tracer cavity. The second method eliminates the Starter Enable Relay too.

Let me make it clear that I am not endorsing the elimination of VATS, just passing out the information. This was also covered very well by Andy (redrose) and others, but wanted to try to make things more clear to you as it seemed you were getting a little muddled up when you said you wouldn't mind trying Andy's VATS sim when you've already had this effectively done by Alvin.

Good Luck and sorry for the long post.