I've read some archived threads here about others who have experienced this problem: the AC is set to a specific temperature with fan engaged and the ignition is then turned off , say for a few hours.

This is a 2010 LS 460 with 16K miles that I picked up a few days ago. Ever since, I have not been able to resolve this issue. When I restart the car, the fan is off and the AC light is off and the temperature is reset to 75 no matter what it was set at before. It requires me to depress the AC switch and reset the desired temperature.

I did change the AC filter after first setting it to recirculate. The LEDs on the outside air and recirculate switch with auto work as they should and the AC filter door opens and closes as it should.

Anyone have any helpful suggestions?

Thanks,

Paul

 

This is just a guess but it could be a bad sensor on the blending door making the car think it is broken, causing the the A/C system to reset every time. I would bring it to the dealer and have a tech take a look at the issue.

 

Thanks Tee. I appreciate your response.

 

temp. and the a/c not coming on for like 45 sec.! I had changed the cabin air filter but did not reset it. I looked in the manual and this is what has to be done.... Start the car, press and hold the A/C off switch for at least 4 seconds, you will hear... beep beep beep. Once you hear this, it has been reset! Works like a charm now. I am also including a link I found showing all instruction for removing, replacing and resetting! Hope this helps! Try this Paul, it might work.

 

You were correct Tee. When the car first starts up, it does a system check on a number of components. There are multiple servos controlling the climate system, and when one of them doesn't report back to the climate ecu, it defaults to the programmed setting which is no fan, no AC, and 75 degree temp. and will do this every time after the ignition turns off and is restarted.

Before I purchased the car, someone put in an AC filter and didn't place the system in the recirculation mode, thereby knocking off a wire to one of the servos. In the case of other Lexus models parts are broken and you're looking at a $1700-2000 repair bill. In the case of the LS460, the wire gets dislodged from one of the servos and the Lexus dealer has figured out a way to not remove the complete dash but to do the repair through the glove box opening, which requires 3 hours of labor. So it ended up costing me $345. to get it fixed, still not ideal but far better than the alternative.

Now I will go back to the Toyota dealer where I purchased the car and see if I can get them to pay for it. All they can say is no.