93 Ls400 Keyless Entry Not Working.

[Mikes515]

Hey everyone! been a while since my last posts. Car has been running great for having 240k miles on it. A while back before winter hit my wireless entry key decided to not work anymore. I have taken the receiver chip out of the box in the trunk and re set it. Replaced battery in the key fob, still no success. I have read that Lexus charges a hefty fee to send out a new key and chip.

Wondering if anyone has had an aftermarket security system installed, as in a Viper alarm, or bulldog system and If so how much it costs and if it is a viable route to take. I am a little leery about taking the custom aftermarket security system route as the LS seems to be quite complex. If anyone has input it would be greatly appreciated. Having to unlock the car by putting the key into the passenger side door every time is becoming a pain!Time to get the wireless system up and running again!

thanks!

[1990LS400]

Oh, how spoiled we have become .... the idea that we would have to use a key to unlock a car door. But I would miss remote unlock too. I was lucky my 90 LS had it since it was optional until the 1991 model year.

There is a diagnostic procedure for the remote and security system in the 1993 LS400 repair manual. I doubt if the problem is the chip or the key. Replacement key/chip sets aren't all that expensive = $274 from http://lexus.sewellparts.com/accessories-catalog/Keys/LS400-1993.html if you register with a car forum member name to get a discount. Do you have two remote keys that both stopped working to unlock the doors? If you do, both key's would surely not die at the same time.

Plenty of people have reported on forums that they have put aftermarket security systems with remote unlocking on the early LS400 -- must not be too hard. Can you unlock the doors using the button on the drivers door? If you can, that would indicate that the electrical system is working enough for you to add an aftermarket system.

[Mikes515]

I know! We are all very spoiled. But here in New England where the weather is beyond unpredictable and a 2 yr old son, having to go to the passenger door every time to unlock the car gets old! If it worked in the drivers side door than it would not be as much of an issue! :) .... The buttons inside on the drivers door do work to lock and unlock the doors. I do not have 2 keys with the wireless capability. I have one that is for wireless and just a plain valet key with no buttons. I only thought that it had to do with the chip/ key because upon purchasing the car it worked just fine. Now it does not at all, New battery in the key fob, re seating the chip, nothing has seemed to help. If aftermarket will work I think that is the route I would go as it does not seem as expensive.

[steve2006]

You haven't mentioned it and if you have checked it I apologize but is the remote locking slideswitch in the on position?

[Mikes515]

No worries! I know some people don't know every thing to check, but yes the switch was the first thing i looked at to make sure it was ON. Its easy to hit that switch with your knee and turn it off so that was the first thing to get looked at.

[fsuguy]

Hi,

I believe that some of the autoparts chains sometimes have a remote key checker in their stores; you may be able to test your transmitter there. Alternatively, the manual has a test procedure that requires turning the key off and on several times and doing some observation.

Hope this helps.

[VBdenny]

I have 2 keys for my 90 , both with remote. Only one key will unlock or lock the doors remote. I tried a new battery to no avail. At least one still works.