ramensam

Hello. I'm working on a vehicle for customer. It's a 1996 Auto.
The car has a vats issue, when you put the key to on, the securitiy light flashes, then stays on. The car does start, but the injectors shut off after a few seconds.

We purchased a Vats bypass kit which provides the 30 or 50hz signal to the ECM. However, the instructions provided direct me to pins that don't exist on this year vette (Pin 25 on Red Connector). I was hoping you guys could direct me to some proper pinouts for the 96, or better yet offer some other advice on how to proceed with getting it to stay running. A link to the item i got is here http://www.xdponline.com/index.php?m...0d4c890ee76004

Thanks for you help

70ZZ3 96LT4

Did you try a brand new key with the pellet on it?

Tom400CFI

Why don't you fix the problem rather than adding a hokie bypass kit?

Have you checked resistance through the key circuit at the two pin connector near the base of the column?

It's odd that it cranks. It shouldn't.

DinoBob

Sounds like something else to me. See the thread called "retro engine for 1988" for some information about the ECM and spark.

DinoBob

VATS, if I recall, does not even into play once the car is running.

MaxDaemon

Not sure about the Corvettes, but the '91 Cadillac I had would display something like "Security Locked" on the dashboard and not allow you to try starting the car again until the 5 minutes expired.

I found a set of instructions on the web that showed where to put a simple 59 cent resistor in the wire under the dash to bypass it, worked perfect for me.

Take a look at this link - basically says that if the engine cranks at all, it's not a VATS issue.

http://www.corvetteactioncenter.com/...-86-vette.html

MaxDaemon

aaaaand adding a little more info - looks like the 95 and 96 cars had an upgraded version of VATS that actually did mess with the fuel system, so it might start and then die. Here's the thread I found...

http://67-72chevytrucks.com/vboard/s...d.php?t=419649

ramensam

Thanks for the replies so far. The reason we are trying to do a bypass is because we can't seem to get anything related to the resistance of the key to work. We've run thru all the key resistances and the car behaves the same.
The key measure 680 ohms, I've created a chain of resistors matching it and placing it in place of the key in the wiring as well.

We previously had a no crank condition, but that weirdly fixed itself. But now are left with the injectors shutting off.
After reading the thread linked above, it seems to indicate the 95+ vettes communicate via Serial data. Not sure how I can work around this.

FASTAZU

Hope this helps. looks like you would need a 0.680 ohms


List of resistor values on last page
http://www.lockmasters.com/ecommerce...%20Article.pdf

Tom400CFI

All from at least '92 up communicate via a serial data cable. All serial data wires are tan, from the ECM, CCM, EBCM...all tan. You can test them by checking for continuity from one Control module to another.

How did you "run thru all the key resistances ."?

If you did it the way I'm thinking, then I'd say it's something else. Have you drawn codes from the CCM?

ramensam

We had a locksmith who had a device he plugged into the key connector that has a slider which adjust the resistance. He started at key type 1 thru 15 waiting 5 min between attempts.

lt4obsesses

I wouldn't be so convinced it's a VATS issue. it could be a lot of things.

Grounds, Maf, relays, ad infinitum. Best to start with diagnosis based upon a crank, start and stall. If you get tunnel visioned on one thing, it's hard to think objectively.

ramensam

Well, I've checked with a noid light that the Injectors stop right before the car dies if that helps.

Tom400CFI

What is the "key connector"? The tumbler (where you insert the key)?

You need to drop the driver's side kick panel. You need to find the two pin connector at the base of the column, one wire is purple, IIRC, the other may be white? You need to unplug that connector and probe the two pins for resistance, with the key in the tumbler and "ON", and also in the crank position. Good idea to test while moving the key back and forth between ON and CRANK, looking for drop outs.

The entire time you're probing that connector for resistance, with the key in the tumbler, you should see the same resistance at those two wires as you got on your key; the ~680 ohms. If you don't get that, or you get "drop out" in continuity, then there is an issue in the tumbler/key connection, the wires in the tumbler, or the harness down the column.