I have a 1988 GTA 5-speed with VATS and have had no issues last 2 years. Sunday took it for it's first drive after winter with no issues. Tuesday took it to work with no problem, after work it won't start (turn key, it all lights up like normal but turn it to start and nothing). I noticed the "security" light was on but can't say as I've ever noticed it lit before. Tried jumping it just in case but battery was showing as good. The security light does not go out at any point with key in ON position which as I read that means VATS thinks it's the wrong key. I also tried my spare set but that didn't work either.

I think I've read all the VATS threads (and there's several) on this site but nothing was quite the same as my issue that I could find.

I tested Ohms on both keys and it's 1.125 I pulled the harness (2 white wires with orange sheathing) and tested with the key in - 1.125, turned key to ON position and same reading. I did try using one key as a bypass on the same harness (on the side leading to module) and that didn't work either. So at this point I'm thinking it must be the module but obviously would like to confirm that before I try to find one and then have to get new keys coded to it.

Anyone have any thoughts on what to check next? Is it worth trying various resistors with all 15 possible values - this doesn't make sense to me but .....

Thanks for any help

 

Sounds like your module or VATS Timeout. Here is a good read and understanding VATS. It may help you out.

https://sandflylocksmith.com/service...eneral-motors/

Here are the key resistance chart codes. Once you get a new module, determine the code for it and order the key blanks online, then get them cut.




GL
Bob

 

Thanks for the link and info. I figured it the VATS Module but was hoping there was some sort of test as obviously it's not going to be fun to change let alone find one. Does anyone sell a replacement? I see Hawks does a bypass module but sort of defeats the purpose and not sure if that would work for me anyway.

 

Here is a used one from Brocks Camaro...fits 88 GTA. They are out there.
https://www.ebay.com/itm/88-89-CAMAR...kAAOSwsEhbFwp~

 

GM# 16082499

 

Great thanks once again.

 

Just wanted to update the thread for anyone else that has similar issues. I went to the local pick a part as they received a GTA recently and more or less the only part left was the VATS module (seems most people don't want it). Snagged it for $9.20 CDN.

Had a buddy set up 14 different combinations of resistors so I could test it to find the right one. My module was located just above my right knee screwed to the ducting. I couldn't access it enough to remove it without pulling a bunch of the dash apart but I did manage to disconnect the harness and could plug it in to the new module. I started with 1 and turned the key and the security light stayed on. Changed resistors to next one and wait 4 minutes and try again. Ended up being a #10 module. I left the jumper in and could now start it with my normal key. Local key mart stocks the keys for $25.00ea so going to get those made up so I can remove the jumper. Managed to cram both modules back and still reinstall all the covers.

Maybe this winter I'll rip it apart and actually pull the defective one and install the new one correctly but at least it's driveable now.

and a special thanks to Bob88GTA for all the help!

 

Thanks for following up canadamaro! Great info.

 

There's a reason the VATS system didn't enjoy a long lifetime.
Unless the vendor offers a warranty, I'd be skeptical about a used one.
Especially @ $30. And the only way to test it, is plug it in & try.

The question you might consider, is how attractive is your 20+ year old
vehicle as thief bait. If so, consider an aftermarket alarm system.

VATS override is accomplished in two ways:
1) Get a simple cheap override module that puts the required
signal (30 hz, 5v) into the ECM.
2) Reflash the ECM MEMCAL to ignore the VATS input.

Good luck.