akkidy

I recently purchased an '07 RX350 with the navigation package. I noticed that when the climate control is set to dual mode, there is a noticeable difference in temperature for the air coming out from the driver and passenger side vents even when the temperature settings are the same. The air coming out from the passenger side vents is warmer than the driver side vents. On the passenger side, I need to bring down the temperature all the way to 65 before it gets cold while on the driver side, 71 is already cold. Turning off the dual mode makes the passenger side as cold as the driver's side even when set at 71. I have checked all other cars with dual mode climate control system and even checked my friend's RX330 and they all work the same way having no significant temperature difference when setting the climate control in dual or single mode as long as the temperature settings are the same on both sides.

I brought my car to the same dealer twice and they said that it's a normal operation for the RX350 with or without navigation. I request forum members to please help me verify if this is true and check their dual mode climate control. I find it strange that the passenger side air suddenly becomes warm from cold even without changing the temperature setting when shifting from dual to single mode.

Here's how I tested it.
1. I set the climate control to manual mode by selecting medium fan/AC ON
2. I switch off dual mode, if it is already ON
3. I bring down the temperature setting to 71 from the driver side and this automatically adjusts the passenger side setting too being in single mode
4. I wait until the air from the vents become cold on both sides
5. I put my hand directly in front of the passenger side vent until it is cold
6. As soon as it gets cold, I turn on dual mode and I can feel the air becomes warmer on the passenger side vents (seems like it's moving towards heater), but the air on the driver side stays cold
7. I switch off dual mode and the air becomes cold again on the passenger side vents
8. I switch on dual mode and the air becomes warm again

Thank you for your assistance.

barry_s

I tried it on my RX350 with Nav while driving today in 80 degree weather. I found that when I switched to "dual" I had to set the passenger side 3 degrees lower to get a roughly equivalent discharge temp. I suspect that it might be the physical location of the temperature sensor(s) that is causing this. My trip was only about 10-15 minutes so it is also possible that it would equilibrate on a longer trip. I do not consider this to be much of an issue. My wife pays no attention to the setting anyway, she just adjusts it up or down to get to a comfortable temperature.

akkidy

Thank you for checking barry_s. I appreciate it. The dealer did say that Lexus changed the location of the sensor and that's probably why the difference in temperature. I would have wished that if Lexus changes anything it should be an improvement and not otherwise. You are right, it is a minor issue as long as it gets cold by setting the temperature lower. I also do not have that AC fault issue or Check Airconditioning message, which only mean that it is indeed functioning properly. I just thought it was a defect and was beginning to be disappointed with my purchase. Hearing it from another owner of RX350 takes away my concerns. I hear good things about Lexus and it's reliability. This is my first Lexus car and a proud owner. I love the handling and ride. This is a great forum by the way. I'm glad to have found it.