I know there is a bulletin on this for the GS. Mine is a ‘15 with 42,000 miles. Last March this started but intermittently. Lexus did not want to do a diagnostics. This year it happened again, I drove right to Lexus, they tried to tell me it has to do with outside temp, but diagnostic showed a code. They did a reset. It did nothing, when I start the car it is fine, once warmed up only cool air blows. First they said make sure the air is on and you have dual set. It has been in twice, it is getting worse, today it felt like the air conditioner was on when set to 75. I also feel the fan has lost blowing power. I am contemplating calling Lexus directly as there is something going on and my dealer does not seem to be able to figure it out.

Anyone else?