Hello!

I drive a Volvo Xc90 2007 2.4 AWD

Due to the cold weather coming in here I discovered my cabin tempereature was no where near it should be.
I started doing some research, and it seems to be a known problem on the XC90, and in most cases replacing the heater core would do the trick. But not in my case.

Here is what I've tried so far;

- Replaced heater core
- Flushed and refilled coolant system
- Cleaned and replaced the thermistor in the "passenger compartment temperature sensor" (cabin temp sensor)
- Calibrated the flaps and done diagnostic through VIDA

The only error code we found were; CCM-0040 - Air Quality sensor Internal fault
From what I've read, this code is pretty usual and does not have anything to do with my cabin heat not coming up to normal levels.
I only experience luke warm even at the highest temp setting. AUX heater works fine, AC works fine, Blower works fine.

What would be the next step here? I'm kinda lost in what to do next.

 

I know this may sound sound too easy - but have you replaced your cabin filter? If it's 13 years old and clogged with crud, it could be limiting air flow.
Just a thought...

 

Not a bad thought, and I actually did this today also with no luck on the heating. That being said, the cabin filter REALLY needed to be replaced.

 

Most modern cars will set a code for a weak or failing thermostat. That said the first thing I would normally do for lack of heat is replace the thermostat.
Want to do a bit of diagnosis first? Feel the hoses when the engine should be up to operating temp. The heater hoses should be to hot to hold on to, close to 200 degrees F. Are the radiator hoses hot? once again the better part of 200 degrees.

 

What temp is the engine warming up to? There is no heater valve so the hot (hopefully) water from the engine circulates through the heater core all time - the blend doors then allow air to pass through the heater core (and blow warm/hot air on you) or bypass the core.

If you have calibrated you must have VIDA - What temp is the engine when warmed up?

 

I had my car in at the Volvo dealership and they did a diagnosis and calibration, telling me the engine temp and coolant temp was not the issue. I can confirm that the hoses are hot and the pipes leading in to the heater core are very hot, so is the heater core itself.
The engine temp gauge rises steady to the middle and stays there during drive, nothing off here as far as I can see.
Volvo suggested the little fan behind the interior temp sensor shoud be replaced, but the fan works, and the fan itself does not bring up any codes in VIDA.

Edit: I just measured the coolant hoses running through the firewall, they came out on about 130F but it was difficult getting a consistent measurement.

 

running temp of the car is closer to 200F than 130F. Most thermostats start to open at about 180 or 190F. What does your temp gauge say? You should be seeing it come up to full operating temp within 5-10 minutes of driving.

 

I´m not sure where to measure to get most correct temperature reading of the engine. Using my laser I really cant get a consistent temperature on the coolant-hoses but between 130-140 is what I get after driving the car for 30 minutes.

The temp gauge reads fine, rising to 12 o clock pretty fast and stays there.

 

Update:

I did a CCM swap in my car with a module I knew was working from another car.
But, still no difference in my car. Just luke warm at its best.. This is starting to become a mystery.

 

actually ur not alone bruh😎 I’ve got xc90 2007 D5 awd as well
I had the same problem
after making numerous attempts I decided to check my car with VIDA and ccm 0040 says that the problem is in your air quality sensor

I’ve just cut it off and system’s started working properly

before that I froZe my back passengers while driver (me) and front passenger were burning

when air quality sensor is broken conditioning system gets MAAAD, cause LIN 2 starts getting wrong signals from the sensor. As my mechanic said’average lifelength of this sensor is 10 years

THAT’S it

looking forward to hearing from you :”duuuude ! Ur magician !!!!’

 

@EGEnaSTO

Hey man, glad it worked out for you by cutting off the AQS sensor.

My problem turned out to be a faulty heater core, and once replaced with a new one, my cabin is almost too hot.
I were told that the XC90 needs a "premium line" heater core, and the first one I tried were a budget model.

When I got my hands on a BEHR/MAHLE heater core it was like night and day!