I have a 1991 Seville and am mystified - I found a spare key for it and started the car. Drove home and left the window open during a quick rainstorm for say, 10 minutes. Went to start the car and it went into the security loop "Remove Key" Wait 3 minutes, etc Was able to start the car immediately. Now the car is failing to start on a continual basis. Sometimes the car will start after 10 or so tries, other times first time, other times wait three hours. Have tried either key, tried unlocking door with key, parking brake set, etc. (don't know what brake would have to do with it, but it did start one time after doing that, so I mention it.)

Could the spare key have confused the security system? I have tried using canned air to blow into lock, cleand keys, etc. Any suggestions would be appreciated. By the way, I do not own a FOB for it. Have been suggested to unhook battery and have not yet done so.

Thanks in advance for all replys.

Andy

 

The same problem occurred with my 96 Eldorado. As with mine, your problem is likely with the VATS key system, part of the theft deterrent system. It was not confused by the spare key nor likely connected in any way to rain from an open window. The VATS resistor reader is likely not properly reading the resistance value of the key pellet. If cleaning the pellet didn't help, the resistance of the key can be duplicated using resistors (from Radio Shack for example) and the resistors wired in, effectively bypassing the resistor pellet on the key. I own 3 Cadillacs (96 Eldo, 90 Seville, 89 Allante) and using some info found on the net, assembled resistor bypasses for each of them and wired them in without problems. The keys work as normally expected, but the resistance is provided by the bypass. This means, of course, that any other key with the same "cut" will work, so that part of the theft deterrent system is now rendered inoperative. The only other option I can think of is a pricey new key from the dealer.

Go to this website for detailed photos and instructions: http://vats.likeabigdog.com
It's really not a very difficult job, but study the instructions and photos for wiring. Hope this helps.

 

Thanks so much for the great reply!!! We took the ohm meter, did the analysis and went to
Radio Shack and picked up a pack of 5 resistors for a big fat 99 cents. You can actually put these in a row to get the right resistance. We then cut the two white wires and placed the resistors across them and the car started right up.


The article makes a really good point. You can actually make up one of these kits in advance and cut the white wires, put the resistors in place and check to make sure all works. Then, reconnect the white wires with some quick connects and you still have use of the security system. Keep the resistor wire in the trunk and when that sad day arrives when your car won't start because the ingition won't read the key, you simply reach into the trunk and make the 1 minute switch and you are still driving your car. I will be doing this for my daughter who also owns a '91 Caddy that daddy bought for her

I'd like to suggest to the administrator that the site listed in the previous post might be considered for a "sticky" as it is a wonderful solution to an up-and-coming problem for aging GM products.

 

ok i have a related question.i have 2 sevilles a90 and a91. the 90 is at the mechanic getting the lock changed(i just found this blog) he said the security system was makeing the ignition not fire properly and eventually quit all together. the91 is now not running right either. it's misfireing on exceleration and ive tried everything filters,and what not. could the 91 be doing the same thing? help would be greatly appriciated

 

I'd like to suggest to the administrator that the site listed in the previous post might be considered for a "sticky" as it is a wonderful solution to an up-and-coming problem for aging GM products.