Intermittant no-start AGAIN!!!

[Nige]

Just when I thought all my problems were over! A few months back you guys were extremely helpful in resolving the problems I was having with my '87 convertible.

Like most owners (it seems) I was suffering the infuriating intermittant no-start fault but, having followed your advice and changed out just about everything possible, it went away. Yeah!!

Last month it started (or rather didn't) again!

Although there were no error codes showing, I borrowed an EZ Link to discover that Code 46 was causing the problem. Yep! It's the dreaded "Vehicle Anti Theft System failure" fault again.

So, here's where I am now... I've done some digging around and have been told that the fault is definately with the VATS module. Before I go ahead and order one up from Eckler's and pay to have it shipped to the UK, then pay Customs Duty and local taxes etc., etc. I thought I'd ask if you have any other thoughts on what the problem might be?

Last time round, I changed the Ignition Lock (barrrel and keys), the battery, the starter motor, the block that sits on top of the steering column (can't think what it is called - although I know what I called it whilst trying to get it fitted!!) and the Park/Neutral switch. The only items I didn't change were the Starter Motor Inhibitor Relay and the VATS module.

This may sound a very silly question, but just where exactly is the VATS module located? I've hunted around as best I can but either I'm missing the totally obvious, or just haven't found it yet.

I did find something else that I can't identify though and have posted some pictures of it at: http://www.btinternet.com/~nigelstreeter/whatisit.htm If you have any sugesstions, would you please let me know.

Any help/advice would (once again) be most gratefully appreciated.

Best wishes from the UK.

Nige.

 

[Magmotor]

Moduel is located behind intrument panel right side. <see pic-#12> What's it not doing??

I couldn't load up the pics you put on that site....

 

[Nige]

Cont'd...

Sorry 'bout that Magmotor, didn't enter the links to pics correctly - story of my life!! All sorted out now.

What's it not doing? Well, it goes like this...

Key in, ignition on, everything appears normal. Turn key to start and nothing happens - zip, nicht, nada!

Try this over and over for next few minutes/days/weeks (leaving at least five minutes between attempts in case it's the VATS lock-out), get frustrated and walk away. Go back for one more "last chance before I torch the thing" and it starts without hesitation!!

Turn it off and try again - it starts. Turn it off and try again - it starts. Turn it off and try again - it won't start!

Plug in EZ Link, find fault 46 (VATS failure), turn ignition off and back on, re-scan system, fault still exists. Try again, re-scan, fault cleared (Yippee!). DON'T START CAR. Turn off ignition. Turn back on and re-scan - fault 46 back again.

And so it goes on!!

Frustrating or what?

After much head-scratching and a whole lot of new parts, plus trawling through this Forum, I've come to the belief that it can only be one of two things - the starter relay behind the Information Centre, or the actual VATS module itself - there's nothing else left to change.

I can't figure it. If the module was faulty, surely it would be faulty all the time - after all it's a bit of electronics which should either work or not?

By the way, just to make sure it's not an earth problem, I've also fitted an extra earth strap between the block and the chassis.

Thanks for the diagram. Is the module located behind the Information Centre or behind the r/h dash - it isn't too clear from the drawing?

Many thanx for your help.

Nige.

 

[Gman]

Nige, perhaps there are some poor connections inside the module due to dirt/dust, soldering? I just took apart the control head of my elec. a/c because I was having intermitten problems. I cleaned it up with electronics cleaner from Radio Shack and voila, no more problems. I was also prepared to solder any connection that looked like it may cause a poor connection, but all looked good. I will confess that I'm clueless regarding the vats module and I don't know that it can be taken apart and cleaned. I hope someone here can help. I wish you good luck.

 

[Magmotor]

Forget about the VATS. It's working. Here's where I'd check to make sure all 8 red wires are making a solid connection. It's directly under the battery. Take the side panel off and remove the battery for a clear shot a cleaning the whole bus. One is the starter motor and if this bus gets anykind of rust or corrosion all kinds of electrical problems will happen. This supplies voltage to 8 different systems on the car.

I have no idea what that moduel is. Does it have a part number on it. Doesn't look like an original GM mod.

 

[HPG]

Did you try the VATS bypass, it's in the Mid America book. I put one on my 88 and it never failed on VATS.

 

[Nige]

Forget about the VATS. It's working. Here's where I'd check to make sure all 8 red wires are making a solid connection. It's directly under the battery. Take the side panel off and remove the battery for a clear shot a cleaning the whole bus. One is the starter motor and if this bus gets anykind of rust or corrosion all kinds of electrical problems will happen. This supplies voltage to 8 different systems on the car.

I'll try that. Unfortunately I won't have the time to do so until next weekend - I've got friends over this afternoon and it would be highly anti-social of me to spend the time with my head firmly buried inside the 'Vette (- and I'd miss out on the beer and food!!)

I have no idea what that moduel is. Does it have a part number on it. Doesn't look like an original GM mod.

'Fraid not. It doesn't look like an after-market part as the connector that plugs into it looks factory fitted. Still, maybe I'd best just leave it alone and worry about it some other time?

Will let you know how I get on next weekend.

Originally posted by HPG
Did you try the VATS bypass, it's in the Mid America book. I put one on my 88 and it never failed on VATS.

I don't think it is a key problem as both the ignition lock/cylinder and keys are virtually brand new. If my memory serves me right, the bypass imitates the resitance of the key pellet, to allow you to start the car with an un-pelleted spare key.

Does the bypass switch that MAD markets completely disable the VATS, or just allow you to use a copied/blank key?

Whatever, thanks for your help - much appreciated.

Cheers for now.

Nige.

 

[HPG]

If you have the newest Mid America book, it's on page 4-37.

 

[RonV87]

Do you have one of those aftermarket battery disconnect switches with the green knob on top? I had one on a 78 and one on an 87 after that and both caused me no start problems. If you have one installed try removing it.

 

[Nige]

Hi Ron, thanks for the info 'bout the battery disconnect switch - unfortunately I don't have one of these fitted (I wish it were that simple!!).

Further to the Mid America unit... I've been in contact with them and the unit they sell is an upmarket version of the standard key bypass unit. It doesn't bypass the actual VATS.

I've still got to try magmotor's suggestion, which I should get to next weekend.

Keep your fingers crossed for me!

Many thanx.

Nige.

 

[FourDown]

I had an '86 with the exact problem you describe. Lived in San Jose and dealer replaced about 13, 227 parts, wires, and modules because he had no clue as to what was wrong. He replaced keys and pellets, steering wheel, VATS and on and on until he finally told me (get ready) that the problem was a "known" one and that there was no fix and that I would just "have to live with it".

Going thru a mid-America catalog one day, I saw an item that said "Hey Don...want to fix that intermitent no start problem on your '86 Vette?" So I bought this $13 piece of something that fit between two wiring harnesses and the problem went away forever (or until I sold it in '93)

It took 11 seconds to uncouple the wires and 14 seconds to put the Mid-America piece in. Was a piece-of-cake and I suggest you try them or call them.

Definately worth it.

 

[Nige]

Update... Update...

OK! So it's Sunday afternoon and I have finally found where the VATS module is hidden!!

It is buried behind the right-hand (passenger) dash - you know, that hideous lump of black plastic that sticks out into the car!

Getting into it was not much fun. I cannot for the life of me find out how to remove the r/h lower dash assembly (the carpetted bit) but, having traced the wiring from the ignition lock into the huge loom behind the radio, I figured this could be the only place. So, as a last resort, I took the dash top off and there, hiding behind the dash-pad was this little grey box. I removed the two screws at the top of the dash-pad and that gave me just enough room to remove the module - at bl**dy last!!

So, I have just ordered a new one but am away next weekend so shan't be able to fit it for a couple of weeks - mind you, it will probably take that long for the British postal service to deliver it!

Magmotor: I checked the eight reds and they all seemed OK, but I re-did them anyway. Thanks for the tip.

I'll let you know how I get on when it arrives.

'Til then, thanks again for all your help.

Nige.

 

[Nige]

SUCCESS AT LAST!!!

I thought it might never happen but, at last, the 'Vette is up and running again - and starting first time, every time!!!

- although not without one last hitch...

I ordered a new VATS module from Corvette Central and, because mine is an '87, figured the one advertisied (84 - 89) must be the one (makes sense, doesn't it). I also ordered a new r/h headlight motor at the same time - not the simple two-wire job, I had to search for nearly a month to find a three-wire!!

These items finally arrived last week and, guess what...

The VATS module had a different connector configuration to mine and the top mounting point on the h/l motor had been smashed off in transit!!!!

It turns out that from '86 to '88 they used a different module, in a grey casing, not the usual black - and guess which was fitted to mine?

In desperation I 'phoned all the Corvette Spares Dealers in the UK again and found that a company called Claremont Corvette actually had the right unit in stock. The price: £250.00 + Tax - that's $475 !! and I also had to buy two new keys as the code was different. I've put the other one on Ebay, so I might get something back for it.

To cut a boring story short, I fitted it today (after watching England beat Australia in the Rugby World Cup Final - well done lads!!) and it worked perfectly. I also managed to get the h/l motor fitted and it also is now OK.

So, all in all, a very successful day. Now all it needs to do is stop raining so I can get the roof down and enjoy!!!

Thanks again guys for all your help over the months. It's been worth it.

Nige.
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