nickderosa

Hi All, I recently picked up my 2007 LS460 and noticed there was something funny happening with the A/C.

Symptoms are:
- A/C system not coming on when the car is started (delayed about 1 minute)
- System always being reset to 75 degrees
- Heat not blowing on passenger side
- Code B1441 "Air Mix Damper Control Servo Motor Circuit (Passenger Side)"

Solutions tried:
- Making sure the air filter automatic door is operational (yes)
- Replaced A/C amplifier

I just purchased a used servo motor off eBay (claims to work), but I cannot seem to locate where it goes. The most helpful diagram can be found here (just mirror the image for LHD vehicles) --> http://toyotamarket.ru/jp/431140/001/1/8714/2/87106H/ -- it's in Japanese, but the diagram is still helpful.

My question now is, has anyone replaced one of these on their own? Is it reasonably feasible?

hlheaton

Here is a parts locator diagram

nickderosa

hlheaton

Also try this diagnostic, which you can run on your car to see which servo is malfunctioning.

hlheaton

Trouble code B1441 indicates trouble with "air mix damper servo (for passenger side HOT)". Check that the linkage is not binding. If it still doesen't move, replace it. I seem to be having the same problem for the drivers side. Mine is stuck on cold, and it gets pretty cold in the winter.

nickderosa

hlheaton

Can you describe the "burping" operation?

nickderosa

Sure! We had to take the engine covers and air inlet off to access the overflow tank where the cap is. With the front end jacked up, we put a funnel in the overflow tank and started filling it with distilled water (regular 50/50 coolant will be used once I replace the radiator). Turn the engine on and also put the heater on full blast. Keep filling the reservoir until it doesn't take any more water. Air bubbles should come out the top of the funnel. Once the bubbles stop, rev the engine to around 1500 rpm and more air will come out. Just keep doing that until no more air bubbles.

You'll notice the heater blowing super hot air and the engine temp stay in the normal range. Hope this helps!

rx3502007

Is there a diagnostic available similar to this for the RX350? It sure would be helpful as my wife's is having heating issues currently.

hlheaton

Probably. Go to techinfo.toyota.com, and for 20 bucks you can get access to the factory repair manual for your car for a few days, enough time usually to diagnose whatever is wrong.

hlheaton

BTW, most people that have had heating problems on this forum have found that a cooling system flush and fill fixes the problem. Use only Toyota red coolant as the green stuff causes corrosion in these vehicles. Low coolant levels also can cause this issue. Also check for air pockets in the heater core. If you have a Toyota techstream OBDC connector and software (search on ebay, its not expensive) you can also command each actuator individually to move so you can see if it is working.

Kingrb18

So did you fix the problem after replacing the servo?
So your ac turns on right away? And the temperature setting holds from previous setting?

Thanks!

nickderosa

I did not replace the servo motor. Turns out, low coolant was the issue (more specifically, air got into the system from a radiator leak). Once replaced and topped off, the ac turned on right away to my previous settings. Worth checking on in case this is your issue too. Good luck!

Kingrb18

You had code 41 right? And thats the air mix door position servo. And tou end up just topping the coolant and fixed the problem? Like the delay in turning the ac system on after you start the engine??

Thanks!

parm

can someone help me on how to replace the blower assembly along with the air flap on 2013 es350. Also need to change the Hvac servo motor. Passenger side get cold air while hot on the driver side.
Went to Lexus dealership and they ask ask $300 for diagnosis plus the part and labour.