So I was browsing the Lexus Service Menu on my Nav unit, and noticed a CHEK only next to Audio H/U; everything else was OK. To the best of my limited knowledge, nothing is really wrong with the Audio in my car.
When I pushed on the CHEK, it had error codes dated 2005 and 2009!
So I cleared the codes. I guess I should have taken a pic for this forum before I did that..

Now this 2005 LS430 had been to multiple Lexus and Toyota dealerships over the years.
Does anybody there ever check and clear those codes?