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Theft Deterrent System Problem

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Old Jun 5, 2009 | 01:06 PM
  #1  
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Default Theft Deterrent System Problem

I sure hope someone can lend a hand! I have a 95 LS with approx 180k on it. The car is a dream, normally. The last couple of days though, the alarm system will just intermittently go off while its just sitting in the parking lot where I work. I work at a secure facility, so i don't have a problem with anybody messing with it. In the last two days it has gone off three times for no apparent reason.
If something electrically is starting to fail does anyone know how to disable the system?
Thanks to anyone who can help!
Jeff
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Old Jun 7, 2009 | 08:58 AM
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Just my .02 cents, I am having the same sort of problem on my 92' Ls I'm refurbing. I think it's the actual door courtesy switches, as they sometimes like to think the door is opened, or closed even though they aren't. I was able to simple unbolt them with a 10mm, and spray MAF sensor cleaner in there, move the plunger up and down, and little success. The doors recognize that they are closed, but sometimes when they are open, they think their closed. Anyways, I couldn't figure out for the longest why my alarm went off 3 days in a row, then I put 2 and 2 together.

Maybe start here.. http://www.lexls.com/tutorials/elect...fcourtesy.html

About disabling the alarm, you just have to not lock the driver's door. Anytime it's looked, it seems that the security system is activated.
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Old Jun 7, 2009 | 09:18 AM
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Thank you 3UZFTE for your .02 cents!
I pulled the Alarm System fuse two days ago as a temporary thing so I could lock my car when I'm out. Unfortunately, that kills the electric locks, trunk and overhead light(when the ignition is off) which is inconvenient but at least it allowed me to drive it.
I will give this a try and let you know when I have some feed back.
Thanks again!
Jeff
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Old Jun 7, 2009 | 10:26 AM
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there is a green wire located in the panel at the left under the dash, pull back the carpet and ground that wire,now ur anti theft will be disabled..its the only solid green wire, make sure to disconnect the negative on the battery b4 u start to do this
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Old Jun 7, 2009 | 10:31 AM
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here is a pdf file in case u need it
Attached Files
File Type: pdf
1992LexusLS 400.pdf (279.4 KB, 1325 views)
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Old Jun 7, 2009 | 11:00 AM
  #6  
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Is it a heavier gauge wire (14-12 ga) in the fourth connector (bottom) down? I found a lot of smaller solid green wires, but they all had some other ident on them, i.e. silver dot, brown stripe, etc. If so, do you try to remove it from the connector and then take it to ground?
Thanks,
Jeff
P.S. I discovered the mechanical door switches apparently were eliminated in '95 as they don't exist on mine
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Old Jun 7, 2009 | 11:59 AM
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its the only solid green wire, no other stipes or markings on it, and they make these types of splicers that u can just run a parallel wire by crimping it into the connector and then grounding it that way
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Old Jun 7, 2009 | 12:13 PM
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Thanks for the pdf and addl info! If I am reading the pdf correctly it appears it may disable the power unlock also. Is that your take?
Thanks again Python and 3UZFTE!
BTW, I've seen some info on other forums about taking all metallic objects from the armrest consol as apparently there is a factory sensor there also. Have you heard anything about this?
Thanks again!
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Old Jun 8, 2009 | 10:16 AM
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Originally Posted by JT's LS
Thanks for the pdf and addl info! If I am reading the pdf correctly it appears it may disable the power unlock also. Is that your take?
Thanks again Python and 3UZFTE!
BTW, I've seen some info on other forums about taking all metallic objects from the armrest consol as apparently there is a factory sensor there also. Have you heard anything about this?
Thanks again!
Nice to know they were eliminated on the newer cars. Yes, I have heard of this sensor. I think I also read it can be turned to be less sensitive, but maybe not.. Anyways, I don't think it would hurt to try.
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Old Jun 8, 2009 | 10:47 AM
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Do you, by chance, know how to get to this sensor to turn down its sensitivity? I am also wondering if it can be eliminated from the circuit. So far the parking lot has been quiet...knock on wood!
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Old Oct 1, 2010 | 01:49 PM
  #11  
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The gremlin is back again! jeez this sux!
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Old Apr 6, 2014 | 02:45 PM
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Hey bro thanks for input.. So the clarify, the green wire is located under the driver-side dash and needs to be grounded? THanks!
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Old Apr 6, 2014 | 05:43 PM
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https://www.clublexus.com/forums/ls4...-lexus-ls.html
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