ddlaz

Hey all. I've been googling this issue for 2 days with no fix. I'm close to spending the money to get an rx330 service manual.

My issue -
Since last winter, the darn dual climate control will only put out heat on the driver's side vents on any warm temperature setting(above ambient), passenger side will only put out room temperature air. Cold A/C will come out of both sides just fine.

AC diagnostics check says code 11, which I've read to be the temperature sensor circuit. I tested the sensor by the knee on the driver's side and resistance goes up and down with temperature, within ranges that I've seen for other thermistors--this one read 1.68 kohm last night. I checked the connector and read 3.5volts going to the sensor. Sprayed in contact cleaner and reconnected it. Still the same error.

Are there two cabin temperature sensors in this car?? if so, where is the second one?
It seems like there is a second sensor on the passenger side that thinks the cabin temp is high so it doesn't allow the air mix control to allow hot air through.

My second theory is that the air mix control servos aren't working on the passenger side. I don't know what servo I was looking at but I could peek a servo moving up and down on the passenger side left knee area under the dash. it would move up and down as I changed temperatures.


One last thing to note - i take it off dual climate control and the problem remains the same. My thinking is that the dual climate control off would mean it uses the one temperature sensor to control heat to both sides of the car.....

crimedog

I have the same problem and was wondering if you ever got this fixed? I'm assuming it's the passenger air mix servo. Has anyone ever changed this out?

vscalais

iTrader: (1)

Same problem in my 2006 RX350 right hand drive (Australia). Help please

crimedog

I checked my a/c diagnostic codes (it's easy, do a search) by turning my ignition on and while pressing the auto and recirc buttons. Hold the buttons until the car starts. The lights on the ac will then flash and the problem codes will display. Mine is a code 31, which is the passenger air mix servo. I think it's a pretty easy, straightforward job. The part is about $90.

vscalais

iTrader: (1)

Thanks crimedog. I found the diagnostic codes. Weirdly mine came back with 00. I also ran the actuator check. All seemed good. So I will pull of the glovebox and see what's happening. Maybe there is a detached airflow pipe. I guess it could happen if someone changed the cabin filter and dislodged something?? What do you think?

Cheers, David

crimedog

that's very possible. I have also read that the right side of the heating system comes from the bottom of the heater core and can build up sediment which will cause no heat on that side. I would find it pretty hard to believe the core could be that plugged up, but I guess if a vehicle had been abused it's possible. Please let me know what you find.

crimedog

To follow up, I have my passenger heat fixed as of today. I assumed it was the air mix servo on the passenger side (by the code I was getting, see post above). I pulled off the glove box, the passenger heater tube (one screw), and the trim plate on the center console (two trim screws). The servo is very easy to get to. After verifying it wasn't moving by adjusting the temperature up and down, I pulled it out (3 phillips screws). I disconnected the electrical connection. Just for the heck of it I plugged it back in to make sure it wasn't the contacts in the connection. Sure enough, it worked. So I cleaned up the connections with contact cleaner, put a little dielectric grease on them and put everything back together. Worked like a charm and saved me from having to buy the servo.

I'm sure it will eventually wear out as it's a common issue but for now it's working great.

vscalais

iTrader: (1)

Any chance of some pics please?

guyrat7

Was about to request pics too (if possible)
I have the same issue where my driver side sends out cold air at 28'c when the passenger side roasts the passenger. My servo on driver side makes a racket all the time and I am sure it needs to be changed.

crimedog

Sorry guys, I only took one picture, of the actual servo. This is on the passenger side of the center console. It sits behind the black plastic heater vent that is held in by one screw on the bottom. Do a search for how to remove the glove box. Very simple job, took maybe 45 minutes.

guyrat7

That's alright. I wonder whether you were able to note down the part number. My driver's side one is dead. Yesterday I turned the heat up to maximum and got a blast from the arctic when it was 10'c outside.

I am sure i can get one off a toyota and plug in.