NukenGeek

A Technical Service Bulletin (TSB) is issued by an automobile manufacturer when a specific problem on a vehicle has been identified. It provides the manufacturer's instructions on how to correct the problem. I think the amplifier is under the front passenger seat. To fix the bluetooth phone connection problem the amplifier must be replaced with a newer one. You will have to take your vehicle to a Lexus or Toyota dealer/service center, give them the TSB number (AU001-04), and request that they replace the amplifier. However, it may no longer be covered under warranty.

I had the same thing happen to my '97 LX470 in the middle of the night in the middle of nowhere about 2 years ago. The cam shaft that extends from the ignition switch to the electrical contacts broke. It cost me about $600 to get it fixed at the Toyota dealer.

There is a Technical Service Bulletin on this problem in the 2004 LX470: TSB Audio AU001-04. "Some customers may experience the Mark Levinson Audio System remaining muted after ending a phone call using the Bluetooth system. Improvements have been made to the software inside the Mark Levinson amplifier to remedy this condition. Applicable Warranty*: This repair is covered under the Lexus Comprehensive Warranty. This warranty is in effect for 48 months or 50,000 miles, whichever occurs first, from the vehicle’s in-service date. * Warranty application is limited to correction of a problem based upon a customer’s specific complaint." I had the same problem. I found the TSB and the dealer replace the amplifier under warranty.