I bought a used 2008 400h recently. It has Mark Levinson audio. I replaced the factory stereo with Sony XAV100 head unit with CarPlay. Everything was working fine.
Last week the battery died. I jump started couple of times and then replaced the battery. The problem is that there is no volume. Tried radio, bluetooth, CarPlay, usb etc.
The strange thing is, if I disconnect the battery and then connect it, it works fine until next time. But when I stop the car and start again next time, there is no volume.
What could be wrong?
I followed excellent advice in post by @Mamoon here : https://us.lexusownersclub.com/forums/topic/66814-no-sound/
I have checked the fuses and they are ok.
The fact that it works every time after reconnecting battery might indicate connections are ok.
Long short since it was 3 years ago but I'm having the exact same issue. Battery died when i was on holiday, came back to jump start it and the sound from the aftermarket head unit only works on the first turn of the key. The sound has never worked ever since, until I disconnect and reconnect the battery again (sound works one time again) so I'm sure the speakers and connections are fine, checked the fuses which are fine also.
400h: Volume works once after reconnecting battery, no volume after that.
in 04 - 09 Lexus RX330 / RX350 / RX400h
Posted
Long short since it was 3 years ago but I'm having the exact same issue. Battery died when i was on holiday, came back to jump start it and the sound from the aftermarket head unit only works on the first turn of the key. The sound has never worked ever since, until I disconnect and reconnect the battery again (sound works one time again) so I'm sure the speakers and connections are fine, checked the fuses which are fine also.