MelYW

2005 RX330 engine warms up like usual, but I cant get heat into my cabin. HVAC system just blows cold air. Pulled codes from pressing the AUTO and RECYCLE buttons at the same time and it showed 21 and 24.

I think 21 is a solar detection system defect, but I was in the garage so not worried about that. I cant find any reference to the 24 fault code.

I unplugged the battery to try to clear things but it still poured out cold air.

Thoughts anyone? Could it be the air mix servo?

redrocks

It too damn COLD in Minnesota! Your RX can't take it anymore, move south!

dadcat1

Code 24 is also the solar sensor circuit, but is for the driver's side, while 21 is for the passenger side.

lexus114

Hmmmmm...is your radiator low in coolant? maybe the selectors (that choose warm/cold air) behind the control panel are not working.

MelYW

Great to know the code 24 and 21 are both the solar detectors.

Yep on my list to do for tonight is to check the coolant level. I would be surprised if it is low b/c that would mean there might be a leak?

If there is a problem with the air mix servo I would think it would show a code for this? If it is this, is it an easy DIY?

MelYW

Thanks all...looks like I am low on coolant. Now I need to figure out if I truly have a leak. I have another thread for that.

MelYW

No heat due to low coolant from a leaking radiator. Thanks everyone for the suggestions. VIN fell within the extended warranty and TSB. All is repaired and good.