1996 LS400 - Mirror Switch,Door Locks and Trunk release not working with FOB

[TomD]

I am the original owner of a 1996 LS400 with 137,000 miles on it. Always garage kept. Just yesterday the fob has stopped opening the truck and door locks and the mirror switch stopped operating, I can lock the doors when I am in the car and it's running with the arm rest switch but the mirror switch still doesn't work. FOB batteriy is OK. Are all of these related?

[Jeremy M.]

I have the generation right after yours, (1998 model), but a quick check of the service manual from my generation yielded a couple possible fixes- attached is the troubleshooting chart in a screenshot, and the relevant pages in case they help for your year LS. 

There is a transmitter inside your fob that might have gone bad, which you can get a replacement from Lexus, and it looks like there's a description of how to program your new fob to your car, which is also one of the files.

Best of luck figuring it out, unfortunately, I think this is about all I can do to help through the internet.

be-153.pdf be-164.pdf

[TomD]

New development with this issue. Still the remote doesn't function but while the car is running, the door locks and and trunk lid open but now the memory seats and outside rearview mirror switch won't work. All these thinks seem to be iterrelated as they all occurred at this same time. Any further advise or should I repost this?

Tom

[Jeremy M.]

I was sifting through my service manual searching for my ECM location and came across a section on the wireless door lock system that I hadn't seen earlier; keep in mind that the component locations aren't guaranteed to be the same; for example, a quick (possibly unreliable) search says that your model year will have the wireless door lock ECU in the rear passenger door lining instead of behind the glovebox.

The only possibility I can think for a connection between the problems you have is the body ECU, so I've included attachments of the service manual sections for my model year, and hopefully the components are similar enough to push you in the right direction.

The below picture is what I found for the location of your generation's wireless door lock ECU

be-152.pdf be-160.pdf be-169.pdf be-171.pdf

[TomD]

Thanks Jeremy. So, do you think all of the issues that I have are related to this ECU?

[Jeremy M.]

It's the only thing that jumps out to me. I won't give a concrete yes/no because frankly, I can't be sure without going and performing the tests outlined in the manual on your car.