I own an '07 IS350 with the Mark Levinson system and navigation. Recently it has begun shutting off at high volume levels such as when you are at freeway speeds with the windows rolled down and the sunroof open. The display on the radio / CD screens will indicate that it is still playing but no sound comes from the speakers. You can turn the car off then back on and the speakers begin playing again. They do not shut off if you disable the automatic sound levelizer function. Has anyone had this happen to them, and what did you have to do to correct the problem?

 

The amplifier should have an auto shut off it detects a speaker could be damaged. The sound auto leveling must be pushing your speakers to their breaking point. Try turning off sound leveling, and keep your volume below 50!

 

I tried your suggestion and you are correct, the system does work with the automatic sound levelizer shut off. But what it is doing now is shutting off with the automatic sound levelizer turned on at medium volume levels like around 29-32 range. Any idea what this may be; is it the signal from the radio or the ASL function in the amp? I do not want to arbitrarily replace an amp and this not be the problem as a new one is about $2000. Is there a way to troubleshoot this?

 

Yes, almost certainly sounds like the amp. The ML amps have been rather unreliable and are VERY expensive to replace at the dealership (as you have discovered). You can get them fixed at United Radio in Syracuse for a flat fee of about $300.

 

Do you know if they or anyone carries refurbished amps for this car? I would swap this one out and send the old one in as a core if anyone does this or if there is another place to get an amp other than the dealership.

 

you might be able to try a few junkyards.