Once again I seem to be cursed by an aging vehicle! Guess it's because most of them ARE old. I again require the assistance of the C4 brain trust that in contained within this site. On to the problem.......

As some may recall, I had an intermittent start problem with the 91. Turned out to be the starter and had it rebuilt. All was well and good until Friday. Left work to run some errands before the gym. Stopped a Lowe's for ceiling paint, got in and went to Celluar Plus for a headset for my Blackberry. When I returned it would not start. No crank, no noise, no click - nothing. While turning the key, I noticed that the Security light remained on. Repeated tries gave the same response. I know, you are saying "VATS - just wait for the required time and retry". Therein lies the problem. Two years ago I had Alvin (PCMforless)do some custom chip work for me and as part of the work the VATS was programed out and have never had an issue! At any rate, I waited 15 to 20 min. talking to the guys in the store and trying out some new phones. Got back in and same result. With tools in hand I went back yesterday. Disconnected the battery, removed the piggyback chip from the memcal, reconnected the battery and nothing - same as before. I went to each door and operated the lock manually, checked the and reset plungers even opened and shut the hatch just to be sure. Nothing. I tried to set of the alarm (horns) by locking the doors and reaching in to open them - no alarm. All accessories work (lights, radio, etc.) and the Security light stays lit. The only code was H46 (history VATS code).
Sorry to be so long winded, just wanted to give the details.

Ideas?

Oh, yea... I have ideas...

The VATS cannot be removed from the chip. It is part of the CCM and if it doesn't give satisfaction, the engine won't start. Period.

I agree, going back to the original chip is the best bet.

Now... check the key. If you have another, test that. With time, the little chip on the key wears out and won't make contact with the code reader inside the cylinder.

Also, clean it. If it is a bit oily or icky, it won't work.

The H46 tells me that VATS is not happy. Do you have the Helm Manual? If so, check the troubeshooting flowchart for that error.

The upside is that you are not getting the CCM comm error (H41??, I don't remember).

If none the above works, take a VOM and read the resistance on the key chip. Get resistors that match and replace them on the harness from the cylinder to the CCM. You can find the wire under the left knee bolster. It consists of two very thin wires on a single harness with a pin connector, near the base of the column. IIRC, the wires are either light gray or white. Both the same color, regardless.

Replace your resisters on the dash side of that harness. It will trick the CCM into thinking the VATS has been read.

Now... finally... The only way to effectively get rid of VATS is to have the CCM programmed out.

The way it works is like this:

1. Key goes in, chip makes contact inside cylinder.
2. Driver turns key, CCM reads key.
3. CCM sends good/bad to ECM.
4. Engine starts or does not start.

Now... one last question... is this a manual or automatic? If it's a manual, I wonder also about the clutch switch.

The entire lack of anything could be that, or, the automatic park lockout, too.

First off, I forgot to mention it is an auto. Good advice on the key. I did clean it and sprayed the lock as well. I don't have a back up but will have the original read and another one made on Monday and give it a try.

Thanks for pointing out some of the obvious things I overlooked.

naaah, it's a lot easier, the starter enable relay is only looking for a switched ground from the CCM. http://www.vatssucks.com/
On that site, click "starter enable relay" for 90 Vettes, you'll see some pictures.
You either put a ground on that relay wire or even easier, pull the relay. It's one of the 3 relays left under the steering column, and of those 3 the one closest to the steering column. (boy, I am sure, there must be an easier way to put that in a single sentence)
Pull off the relay-cover and you'll see a little moving piece, that will make a connection when the relay is powered.
You can use a match or a little piece of plastic to make a permanent connection. The little metal plate will be in an unpowered state and you'll have to move it over to the other side and secure it with the match from behind. Just make sure to use something non-conducting.
Put in the relay and it should fire right up and get you going. I tried it on my own 91 just in case and it works.

This will only work with the VATS removed chip.

VATS on the 1991 will not apply to that site. It is held within the CCM and that controls it via the ECM, as I outlined.

It works, trust me. I did it in practice not in theory!
I do my own chip burning, removed VATS and shorted the relay, just like mentioned on that site.
If Steel_Blue_91's chip has VATS removed it'll work.

OK, here's the deal. Not VATS, not starter enable relay, none of the above. Column lock cylinder was shot and needed to be replaced. It'll be back on the road soon.

Thanks for the ideas and help.

That's RARE.

For those reading, the lock cylinder actually pulls a shaft. That shaft then activates the start switch, about half way down the column.

Cylinder broken, not much happens. A purely mechanical failure.

Quote:

I stand (well, sit actually) corrected.

I woulda sworn that the VATS on the 91 on up didn't have that relay.

Very interesting. I guess I should revisit those schematics more often.

My bad...

Quote:

I've had similar VATS issues on my 92. First I bypassed the chip with the Ecklers unit. It happened again. So this time I replaced and shorted the starter enable relay. It's happened once or twice since then but not regularly. The last time it was actually the battery needing replacement.
I'm thinking that I'm going to re-burn a chip taking out the VATS.

Anybody else here that has done that have any experiences to share?

Do you have an aftermarket remote start or alarm?