My 91 had the same problem when i got it,the dealer wanted $121 dollars for the new sensor(screws right into the coolant reservoir)I notices a small crack right around where it screws in.I bought a whole new reservoir with sensor at a salvage yard for $25.no more coolant level light
there's a guy on ebay that sells rebuilt climate controls I believe his reserve price is $150 plus $15 shipping and $100 deposit refunded when he recieves your old unit or you can have him rebuild yours and not pay the deposit;but your heat or ac wont work until its reinstalled.heres link as long as it lasts http://cgi.ebay.com/Lexus-LS400-Climate-Co...1QQcmdZViewItem
mine is flawless,it was really easy to install....the link doesnt seem to work;but if you do a search for ls400 climate you'll find it,the guy is J.Eichmann
I had the same problem,two discs were in one slot,I just popped the door open and messed with it until i got it to come out far enough to grab it and pulled it out,fixed the two cd's in one slot and all better