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Keyless entry not working good

 
Old 09-02-09, 05:43 PM
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ls_lextasy
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Default Keyless entry not working good

im not sure if anyone else is experiencing the same problem but mine stoped working but once in a while will work. i know its not the battery in the key remote cause i just changed it. could it possibly the remote itself or the car sensor? any possible convinient way to fix this?
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Old 09-02-09, 06:00 PM
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What about the infamous trunk wiring harness problem. Could this be related to it?
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Old 09-03-09, 12:04 AM
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Mine didn't work either. I opened it up and bent the metal contacts up so that the battery would be a lot tighter in the key. It works all the time now!
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Old 09-04-09, 08:52 AM
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I've got the same problem. Never worked when i bought the car. Then i changed the battery and it worked for a week or so. Then i cleaned the car and also took out the driver seat to adjust some noise problem with a spring. later that day when i was finished the remote did'nt work anymore. Dont know if it has anything do do with the seats but just wanted to mention. Maybe be som electric issue or something.

I just opened the remote today and adjusted the metal contacts but i dit not work either.

So would be nice if anyone knew what to with this problem? :-) I dont think its cheap to go ask a lexus dealer for some new remotes hehe..
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Old 09-05-09, 11:03 AM
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i dont think it would be the batter connection because when i press the button i can see the little light on the remote light up. idk it works every now and then. is there like a sensor somewhere in the car for just the alarm or the remote? im gonna clean out my remote and make sure everything is connected. maybe that will work
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Old 09-05-09, 12:02 PM
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Originally Posted by ls_lextasy View Post
im not sure if anyone else is experiencing the same problem but mine stoped working but once in a while will work. i know its not the battery in the key remote cause i just changed it. could it possibly the remote itself or the car sensor? any possible convinient way to fix this?
You have a 99 LS, right?

For my similar 2000 LS, there are 17 pages in my repair manual devoted to toubleshooting the keyless entry system including six pages on intrepreting the results of the self-diagnosis procedure. Just one of the wacky actions to put it into self-diagnosis mode is to turn the ignition key on and off nine times!

There's no way I could scan all this stuff and post it on this forum. It is very difficult to scan just one page of the thick manual -- doesn't fit on my scanner unless I would break its cover off.

I suggest that get access to a repair manual -- either hard copy or on-line like on Lexus Techinfo. I think I remember forum member qewani1 saying he had an electronic copy of the repair manuals for his 2000 LS400 but he hasn't been on the forum since Aug 10th.

The keyless entry for the 98-00 LS are probably the same. There were several different keyless entry systems used on earlier LS400s including the one on the gen 1 LS400 that had the ROM chip that could vibrate loose.
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Old 09-05-09, 01:32 PM
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i have the 91' ls400 so you're talking about a chip inside the remote that can go loose? can it be fixed? i got ok solder skills but i guess its very small components in the remote. dont know if its possible to into the print circuit?
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Old 09-05-09, 02:05 PM
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Originally Posted by Rollaboy View Post
i have the 91' ls400 so you're talking about a chip inside the remote that can go loose? can it be fixed? i got ok solder skills but i guess its very small components in the remote. dont know if its possible to into the print circuit?
The ROM chip I am talking about is in the keyless entry receiver behind the trim panel on the left side of the trunk -- I do not know if the same system was used on European models.

The keyless entry system on the U.S. gen 1 LS400 was not very reliable -- subject to interference. The keyless entry on my 90 LS never worked in some shopping centers even after the ROM chip and all the keys were replaced under warranty.

The last time the Lexus dealer mechanic worked on the keyless entry in my 90 LS, he failed to properly seat the ROM chip in its slot. The keyless entry started working intermittently in the late 1990s and started not working at all when the air temperature was below 32 F. / 0 C. The person who bought the car from me in 2003 quickly found that the ROM chip had been poorly seated in its slot and had vibrated loose.

My understanding is that the 98-00 LS keyless entry does not use a replaceable ROM chip.
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Old 09-07-09, 08:27 AM
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LOL. Just found out today that somehow i must have touched the on/off button for the remote inside the car. So today i switched it on and now it works :-P All those buttons :-D :-D
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Old 09-08-09, 08:08 PM
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HAHA, Great stuff.

Keep in mind that the remote WONT work if the doors dont close completely either!
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Old 09-09-09, 11:57 AM
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Ahh okay smart. But i was wondering if its possible to get the blinkers to work when clicking the remote? Sometimes i think its hard to hear if the doors are locked.. its not that cool that you got to stop up and listen to make sure the car is locked. Or even look inside the car or grab the doorhandle.

I mean.. The cool thing about a remote is to go a few meters away from the car and just push the button without pointing the remote towards the car. But i think this remote is very sensitive.

In other cars i've owned without keyless entry and the fitted it with a cheap china keyless entry system they always work, and also from a long distance.
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Old 09-19-09, 09:39 AM
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Originally Posted by Kansas View Post
The ROM chip I am talking about is in the keyless entry receiver behind the trim panel on the left side of the trunk -- I do not know if the same system was used on European models.

The keyless entry system on the U.S. gen 1 LS400 was not very reliable -- subject to interference. The keyless entry on my 90 LS never worked in some shopping centers even after the ROM chip and all the keys were replaced under warranty.

The last time the Lexus dealer mechanic worked on the keyless entry in my 90 LS, he failed to properly seat the ROM chip in its slot. The keyless entry started working intermittently in the late 1990s and started not working at all when the air temperature was below 32 F. / 0 C. The person who bought the car from me in 2003 quickly found that the ROM chip had been poorly seated in its slot and had vibrated loose.

My understanding is that the 98-00 LS keyless entry does not use a replaceable ROM chip.
i was wondering what that white box was. cause i was installing an aftermarket sub in where the old one is and i saw that box there. the only problem is that the sub is a 500watt and it puts a lot of vibration through the car and i was thinking that it might have loosened something up maybe. i am going to get dynamat put in. is there a way of taking the cover off cause i couldnt see any screws for it
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Old 09-19-09, 09:42 AM
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Originally Posted by Rollaboy View Post
LOL. Just found out today that somehow i must have touched the on/off button for the remote inside the car. So today i switched it on and now it works :-P All those buttons :-D :-D
theres an off/on button?
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Old 09-19-09, 10:54 AM
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yep it is right beside the trunk release button
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Old 07-17-12, 08:23 PM
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Default Update for a 2005 LS430

Thanks for the info, folks.

On the 2005 model, there *is* an on/off switch, too, but it's located up under the dash, not visible from anywhere unless you have your shoulders on the floor on the driver's side and your feet (I suppose) out the sunroof. Oh, and it's adjacent to the reset switch for the TPMS, which is also not visible. Ask me how I know.

Here's the scenario -- Dad is driving on the highway in his LS430, enjoying the hell out of it after not having driven his car for a while. (He and the car live in different states for the summer.) I'm riding shotgun. The tire pressure monitor alerts us to a low tire. (Hey, that's pretty cool.) No information on which tire, but a quick walkaround makes it obvious it's the right rear. The digital gauge I put in the car for him confirms it. Take the next exit, go to a service station, add air (using the digital gauge to match the pressure in the left rear), and we're good to go, right?

Wrong.

The TPMS has to be manually reset. ("You're kidding, right?" No, the <bleep>ing system isn't smart enough to reset itself.) Drag out owner's manual, trying to figure out location of the switch. Much swearing ensues. Finally find the switch panel. See prior comment about not being visible. I just started poking the buttons there and eventually the warning went away.

The good news -- on that panel, one switch is the TPMS reset.
The bad news -- the other switch on that panel disables keyless locking/unlocking/starting. (I didn't know this until four days later.)

For the rest of the weekend, neither master key activates keyless functions, so Dad is understandably concerned. I'm wondering how much this is gonna cost to fix, and so is he.

Fast forward three days. Ah, the joys of Google. I stumbled across this lovely post, with the pointer about the switch. (Another "You're kidding, right?" moment for me. I've had three cars with keyless entry, and none of them were compelled to have a hidden on/off switch. For that matter, I've had four cars with TPMS, and none of them needed a contortionist to reset the system, but I digress.)

Anyway, thank you to the prior posters. Armed with the suspicion of an on/off switch, I found the panel, pushed a button, and POOF, keyless functions are all present and accounted for. Again, many thanks for the collected wisdom applied here.
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