Alarm Malfunction

[rsn]

When I unlock the drivers door on my 1992 ls400, the alarm sounds. After I lock and unlock the door a few times the alarm stops.

Thanks for your help

[oldskewel]

Random ideas that might help:

- To quickly turn the alarm off, putting the key in the ignition and turning it on seems to work reliably

- I've set the alarm off by: with the doors locked, but a window open, unlocked the door by reaching through the open window

- Faulty door contact switches ("courtesy switch") can cause the alarm to go off. I forget exactly how, but it must be some way that the computer thinks the car is being broken into. You can easily test the reliability of these by watching for the door-open light coming on in your instrument panel. If flaky, I have found that partially removing the switch and cleaning with brake cleaner and a toothbrush can restore good contacts.

- There may be some other electrical switch associated with unlocking the door (do you do it with the key or wireless?) that is working intermittently, causing your problem. The computer may think that the second case above is happening - the door is opening without being unlocked from outside.

Questions - do you unlock with the key or the remote? Does the alarm go off when you unlock it, or when you open the door?

Good luck, Ed

[rsn]

Random ideas that might help:

- To quickly turn the alarm off, putting the key in the ignition and turning it on seems to work reliably

- I've set the alarm off by: with the doors locked, but a window open, unlocked the door by reaching through the open window

- Faulty door contact switches ("courtesy switch") can cause the alarm to go off. I forget exactly how, but it must be some way that the computer thinks the car is being broken into. You can easily test the reliability of these by watching for the door-open light coming on in your instrument panel. If flaky, I have found that partially removing the switch and cleaning with brake cleaner and a toothbrush can restore good contacts.

- There may be some other electrical switch associated with unlocking the door (do you do it with the key or wireless?) that is working intermittently, causing your problem. The computer may think that the second case above is happening - the door is opening without being unlocked from outside.

Questions - do you unlock with the key or the remote? Does the alarm go off when you unlock it, or when you open the door?

Good luck, Ed

Ed:

Thanks for your suggestions. I unlock the door from the outside with a key. The alarms sounds when I unlock the door prior to opening the door.

Thanks again

[nll714]

When I unlock the drivers door on my 1992 ls400, the alarm sounds. After I lock and unlock the door a few times the alarm stops.

Thanks for your help

Hello -

I am definitely not a mechanic or a Lexus authority, but I may have a solution for you. I had somewhat similar thing happen with my 1995 LS400.

I wont bore you with the details on what happened, but tell you what I did that worked for me. Very simply, I loosened and removed the contacts from the battery.....waited a matter of seconds and re-connected them. Problem solved.

I dont know if doing this triggered or reset something in the security system, but again, it worked and no more alarm issues. Hope this helps. Good luck.

[rsn]

When I unlock the drivers door on my 1992 ls400, the alarm sounds. After I lock and unlock the door a few times the alarm stops.

Thanks for your help

Hello -

I am definitely not a mechanic or a Lexus authority, but I may have a solution for you. I had somewhat similar thing happen with my 1995 LS400.

I wont bore you with the details on what happened, but tell you what I did that worked for me. Very simply, I loosened and removed the contacts from the battery.....waited a matter of seconds and re-connected them. Problem solved.

I dont know if doing this triggered or reset something in the security system, but again, it worked and no more alarm issues. Hope this helps. Good luck.

nll714:

Thanks for your suggestion. I will give it a try tomorrow.