After-market alarm question

[Socalerv]

Originally Posted by Z51JEFF

Not a thing wrong with the stock setup,cant steal the car providing the system works.

Since mine has been modified would you please explain the stock security system and how it works?

[mike100]

Originally Posted by Socalerv

Since mine has been modified would you please explain the stock security system and how it works?

basically if you close the door after power-locking it to the closed position, the alarm is active and the security light will blink on the dash for a short time.

The alarm goes off if you open the door- either by smashing the window and opening the door, or if you locked a passenger inside and they exit before you unlock the door. The doors can be unlocked manually with the key, or by the interior buttons.

The horn honks, and presumably, the ignition is disabled.

I don't know exactly all the nuances, but if the passenger side door doesn't lock 100 percent from a sticky lock mechanism, or if somebody manually does the pass side from inside- the alarm might still go off. For sure the driver side lock position is monitored by the alarm.

maybe the BCM monitors lock status, but with the aging door hardware, you might only get 80% lock movement to trigger a falsed lock position. I had to fix my passenger door lock on mine.

[Z51JEFF]

Originally Posted by Kevin

sure you can, but it's just as easy with an after market system too. if someone wants it they're gona get it

Will they be able to drive it away?

[GOLDCYLON]

Originally Posted by Z51JEFF

Will they be able to drive it away?

In a matter of of minutes. All they need to do is break your lock cylinder and carry one of their own. use an inline spliter with the VATS key that they brought stored and drive away. Its the yellow or orange wire that feeds the VATS discriminator box. It isnt pretty but your car will be gone in less than 5 minutes.

[AustinJohn]

Originally Posted by mike100

basically if you close the door after power-locking it to the closed position, the alarm is active and the security light will blink on the dash for a short time.

The alarm goes off if you open the door- either by smashing the window and opening the door, or if you locked a passenger inside and they exit before you unlock the door. The doors can be unlocked manually with the key, or by the interior buttons.

The horn honks, and presumably, the ignition is disabled.

I don't know exactly all the nuances, but if the passenger side door doesn't lock 100 percent from a sticky lock mechanism, or if somebody manually does the pass side from inside- the alarm might still go off. For sure the driver side lock position is monitored by the alarm.

maybe the BCM monitors lock status, but with the aging door hardware, you might only get 80% lock movement to trigger a falsed lock position. I had to fix my passenger door lock on mine.

What I've always found confusing is that '86-'96 C4's had two separate what I would consider security systems. The first was the "Universal Theft Deterrent System" which Mike has described.

The second was the infamous "Personal Automotive Security System" (known at various times as "VATS', "PassKey 1" and "PASSKey2") which GM introduced in the '86 Corvette because the GM locking steering columns could be defeated very easily with brute force. The PASSKey system uses an embedded resistor pellet in the ignition key and if the wrong key is used (and sometimes for a variety of other maddening reasons) prevents starting of the engine by disabling the starter for 2-4 minutes before allowing another attempt. Jumpering the starter won't help because the control module disables the ECM's injector drivers as a second line of defense.

But as others have said, neither of these alone, or both together prevents a determined thief.

I really appreciate everyone's thoughts!

John

[scottfab]

Originally Posted by AustinJohn

What I've always found confusing is that '86-'96 C4's had two separate what I would consider security systems. The first was the "Universal Theft Deterrent System" which Mike has described.

The second was the infamous "Personal Automotive Security System" (known at various times as "VATS', "PassKey 1" and "PASSKey2") which GM introduced in the '86 Corvette because the GM locking steering columns could be defeated very easily with brute force. The PASSKey system uses an embedded resistor pellet in the ignition key and if the wrong key is used (and sometimes for a variety of other maddening reasons) prevents starting of the engine by disabling the starter for 2-4 minutes before allowing another attempt. Jumpering the starter won't help because the control module disables the ECM's injector drivers as a second line of defense.

But as others have said, neither of these alone, or both together prevents a determined thief.

I really appreciate everyone's thoughts!

John

You have it right. No breaking the steering lock or having a splitter for the VATs will be able to guess which one of 15 key codes (resistance) you have. With the built in delay there is a deterrent.
Also it was mentioned that the stock "alarm" goes off. Not true with early MYs. No alarm. That's one reason I installed an after market. It's more of a theft of contents deterrent than for auto theft. However it serves a bit there too since it's much harder for a thief to guess what system you have. At minimum there will be noise that may or may not be ignored by the by-standers.
Best deterrent overall is to keep an eye on it or pay a few $ to have someone call you on your cell if anyone touches the car.

[GOLDCYLON]

Originally Posted by scottfab

You have it right. No breaking the steering lock or having a splitter for the VATs will be able to guess which one of 15 key codes (resistance) you have.

A complete falsehood. A plug in made to order spilter is available all day every day on Ebay. It has a male connection on one end and a female on the other. Once plugged in provided wiht the resistance OHM you choose with the lock cylinder you brought with you. Its thats easy and Ive done it.

[Kevin]

Originally Posted by Z51JEFF

Will they be able to drive it away?

no, it will take a tow truck.

[Kevin]

Originally Posted by scottfab

You have it right. No breaking the steering lock or having a splitter for the VATs will be able to guess which one of 15 key codes (resistance) you have. With the built in delay there is a deterrent.
Also it was mentioned that the stock "alarm" goes off. Not true with early MYs. No alarm. That's one reason I installed an after market. It's more of a theft of contents deterrent than for auto theft. However it serves a bit there too since it's much harder for a thief to guess what system you have. At minimum there will be noise that may or may not be ignored by the by-standers.
Best deterrent overall is to keep an eye on it or pay a few $ to have someone call you on your cell if anyone touches the car.

i can assure you the 90's have an alarm. I've set it off a few times squeezing into the car after some dumbass parked too close to me. don't ask me how, I don't know how

[Socalerv]

Originally Posted by Socalerv

I am with you. I have a cutoff system that will kill the engine if the corect protocol is not followed.

It is tied into the cruise control that scares the blue blazes out of me. If I knew how to reverse I would.

Has anyone seen this type of application before? I want to remove it as if the cruise control on or set button fails I can start the car but it dies in a miinute or so. I would be unable to bypass the kill switch.