Hi everyone, it seems like little information can be found online addressing this problem, I only found one thread here and it's from 2014, another one on justanswer website which for some reason I believe posted by the same person.
here is the problem:
On my newly acquired 2007 LS460 with 220k miles, still drives great, but I'm not able to connect my phone at all as the Bluetooth is not available and it display a message "During emergency call, handsfree system is not available" everytime I try to go to the phone menu in an attempt to connect, interestingly enough, yesterday I was just playing with the car with a scan tool (which is an old one with humble capabilities), I drained the car's battery, it couldn't start the engine when I tried to and, a verbal message played (emergency call ended) I was excited when I heard that and tried again but Bluetooth wasn't available again.
I disconnected the whole overhead unit and tried, the car played a voice message "assistant error has been detected contact Lexus dealer" and that didn't solve the problem.


It's been really long time since someone posted about this problem and I'm hoping that someone has reached to a solution.

 

I believe I was the first person to submit the problem and I never got any feedback on it so I resorted to other options where I found the solution. Took a while but finally figured out that the infotainment unit depends on a computer located behind the back seat near the speakers. It is a lot easier to access it from the trunk. After removing the lining that hides it I was able to disconnect and remove this computer and look on eBay to buy a used replacement with guaranty that if does not work I can return. Replaced the computer restarted the system and all worked beautifully after that. The crazy part is that it took me months to figure the problem out and took 5 min to replace computer. These cars are priceless and wonderful.

 

I believe I was the first person to submit the problem and I never got any feedback on it so I resorted to other options where I found the solution. Took a while but finally figured out that the infotainment unit depends on a computer located behind the back seat near the speakers. It is a lot easier to access it from the trunk. After removing the lining that hides it I was able to disconnect and remove this computer and look on eBay to buy a used replacement with guaranty that if does not work I can return. Replaced the computer restarted the system and all worked beautifully after that. The crazy part is that it took me months to figure the problem out and took 5 min to replace computer. These cars are priceless and wonderful.

 

That's great you figured it out and are now whole. I'm glad you shared your solution with us. Did you narrow it down to the computer before purchasing another. If so, how?

 

Man you're a legend thanks for sharing your experience and now I believe this will be an important source to solve this problem. Here is my input, earlier today I connected an OBD tool (XTOOL D8) to my car and was wondering why I can't see any special function related to the infotainment system same as a BMW for example, however, since it is an (emergency call) that blocks my BL I thought a special function name (MAYDAY) is definitely related, I went there as shown in the photo there is an error in that area but nothing I can do to diagnose using that tool, then I allocated that control module, it's just next to the subwoofer and it's super easy to access and guess what it's name (MAYDAY computer) see the photo, I disconnected all the plugs connected to that unit and yeah I was able for the first time to see that BL option enabled in my newly aquired car, I connected my phone and deleted all others, I reconnected the plugs again and it was only when I connected the white one when the problem appeared again so I kept it disconnected and the others remained connected, I made a call but my voice couldn't be heard. Now another thing that is related, the voice recognition system was not working but now it is working but it seems that it can't hear me as will, so that leads me to believe that the disconnected plug is responsible for the microphone, I can go further and identify that wire which is responsible of intimating that emergency call and keep it away but hey, the whole thing cost 40$ on ebay and I will sleep better tonight knowing that 😁😁.

A ​​​​​​little question, does this system stream music on BL or not? Because I couldn't.
Thanks again and I really appreciate your help.