1998 Ls 400 Alarm Problems

[g_man]

My wife drives a 98 LS 400 and within the last month we have had a problem with the alarm. Everytime she unlocks the door manually when she is outside the car, the factory alarm goes off. The key fob has never worked the 2 years we owned the car, so I can tell you that she locks the vehicle with the electric door switch every time she exits the car. Like I said this has only started within the last month and we have never had this problem before. Any help would be greatly appreciated.

[GRAND_LS 4]

My wife drives a 98 LS 400 and within the last month we have had a problem with the alarm. Everytime she unlocks the door manually when she is outside the car, the factory alarm goes off. The key fob has never worked the 2 years we owned the car, so I can tell you that she locks the vehicle with the electric door switch every time she exits the car. Like I said this has only started within the last month and we have never had this problem before. Any help would be greatly appreciated.

Sounds like the door is not recognizing the chip in the key. The easiest, and cheapest, and most convenient way to go about it is buying another remote off eBay, and reprogramming it. (remote and key are two separate parts, so all you need is another remote). They are close to $25 bucs used. All you have to do is program it, which instructions for are available somewhere around here.

With the remote, you will have the much needed feature of remote locking, and unlocking, and no more alarm going off. However, you might need a working master to program the remote.

[SKperformance]

The door lock does not have a transponder receiver in it only the ignition switch.

Does unlocking the passanger door instead make any difference?

Each door has its own MPX computer.

[g_man]

The door lock does not have a transponder receiver in it only the ignition switch.

Does unlocking the passanger door instead make any difference?

Each door has its own MPX computer.

Thanks Grand and SK for the response. I just called my wife at work and had her go outside and unlock the passenger door. When she opened the door the alarm went off :(

After she silenced the alarm I had her then exit the car, shut the door (unlocked) and lock it with the key manually from outside the car. She waited about 60+ seconds, unlocked the door with the key and the alarm did NOT go off.

Could it be something in the lock switch in the door??

[mark681]

The lock cylinder may be worn. Also, make sure your wife turns the key all the way and holds it there for a second or two.

[mehullica]

There is a switch attached to the back of the lock cylinder to detect manual unloking of the door. I bet it is broken or shorting out.

[Leadfoot]

The lock cylinder may be worn. Also, make sure your wife turns the key all the way and holds it there for a second or two.

That's how I beat the exact same alarm problem on my '92. I have a feeling its the worn key, but just holding it for a second gets around the problem. I have another key but haven't even tried it out as its no problem for me, if it goes off I just try unlocking it again and it always stops. my neighbours love me!

[SKperformance]

A worn key will not cause the problem as it is only the switch on the back of the lock is not correctly shorting the pins to tell the alarm ecu that a door was manually unlocked .

The cylinder needs to be looked at inside the door.