I have a 04 430. When I start in the morning (with AC on) for about the first ten minutes it blows hot air. Then works normaly but will often over a bump start blowing hot again. It is intermittent som mornings works fine. I think I feel a vent doen near my feet open and close but not sure. Blows plenty cold when working.

Any ideas???

 

This sounds similar to my problem that I had a couple of weeks ago. I brought to my Lexus dealer and they recharged my refrigerant. (Cost was about $183) It works fine now. Still takes a bit to start blowing super cold, but I live in Florida where the temp is near 115 degrees inside the car when I enter in the afternoon; so I give it some time. I don't know how hot it is in Maryland but my advice is to bring it to the dealer to avoid the runaround from generic mechanic places. Good luck!

 

Doesn't sound right with the comment about going over a bump. Could be many things. I would take it in to the dealer for sure to have it looked at. May just be something loose, or could be the start of something more serious or just need a re-charge. I'm assuming you are on recirculation, the fan on high (not just auto) and are getting your RPM's high enough to let the a/c system charge? Sometimes short trips don't allow it to get cold enough.

When's the last time you changed your cabin filter? Something else to look at.

 

My bet is on one of the solenoids going south.

 

If you can, stop by an autoparts store and see if they read any trouble codes from the OBD-II port for you. We may be able to offer more if the car is storing trouble codes.

 

Another check you can do is the following:

While sitting in the car insert the ignition key
while pressing down the A/C control auto switch and the R/F switch turn ignition switch ON

an error code (like the 21 in this graphic) may be displayed. 21 reports a problem with the Solar Sensor Circuit... You'd get this error if you doing this test in a darkened garage for obvious reasons. The circuit is also linked the air conditioning system.

 

Bob,

Do you have a list of those error codes?

Harold

 

Yes, but they are vague in many instances.

In the attached PDF you'll find trouble codes in column one.

For example the first trouble code in the column is "B1411/11*1" (where the last number one is the superscript position). The second column is the detected problem. The third column refers to the possible "Trouble Area" and the last column tell you how long the trouble code is stored in memory as system status constantly changes.

The /11 is the code displayed on the AC's LCD control panel. The " *1 " is tied to a footnote at the bottom of the document. And the (05-438) is a reference back to the service manual section and page number.

 

Took the car into Lexus Dealer in Md for oil change and diagnose AC issue.

They wanted 118.00 to diagnose AC and applied towards any repair. They coul dnot replicate problem, swapped solenoids, checked refrigerant (OK no Leaks) & looked at heating system.

No suggestions just bring it back when it occurs again. Oil change was 78.00 no charge for AC diagnostic.

Will see if it occurs again...

 

Had the exact problem with previous 06 ML. Dealer had it for 3 days and after $1100 later problem came back. Didn't want to deal with it so traded the car in for a cpo. Hope you find the problem. A/C problem can be a major pita.

 

senzbar-that was nice service! keep us posted on what happens

 

I just had my 03 4runner in a couple months back to diagnose hot and cold AC.
Service tech found a TSB for the AC relay from back in 05. Switched it out for $197. Now it works fine.

Not sure if yours is same problem.