One side heating ?
 

With the cold snap today we had the heating on in the 2006 XC90. But only the drivers side was blowing warmer air - the passenger side was blowing cold air.

All switches etc were lit and working as expected to blow warm - but no warm air for the passenger :-(

Any suggestions where to look first? Would a code read help ?

Thanks for any input - John

Hello John.

I would say yes to codes, must be through Vida or a car specific reader though, generic readers won't find the climate control units.

I don't know specifically for the XC90 however on the V70 P2 which is a very close relation, it's usually a problem with stuck flaps on the climate unit that can be motor or position sensor failure.

Put money on it being the AQS sensor in the scuttle air intake. Exactly the symptoms I had, about £95 from Volvo.
PIA to get to it as the wiper arms and the scuttle needs to be removed, then a bit of contortion where you really cant see what you are doing to twist to remove the sensor.

Once replaced heating was back to normal.

I would have thought the AQS would have thrown a fault code but may be wrong.

Hope it helps :regular_smile:

Found a YT video on replacing the AQS - does look fiddly - albeit straigtforward. Might be good to get a code read to see if it could be something else.

How easy is removing the scuttle to get at it - I have never done that ?

Scuttle is easy, the PIA is the wiper arms ... you really need a puller.

The AQS removal, I ended up getting my daughter with small hands rather than my shovels to twist it out.

Further digging finds the thread below - where Clan and others state....

"The AQS will not be the cause but likely to be i wouldn't know about that , but his first problem with blowing too cold one side has nothing to do with the AQS just about all the cars fitted with them over 8 years old have the AQS failed fault code and contunue to work properly . The fault is probably a faulty driver's side air temperature flap motor"

Any thoughts on that chaps?

https://www.volvoforums.org.uk/showthread.php?t=246271

Can only advise that in my case after the AQS was replaced in mine, the hot air was restored, even tried unplugging it and cleaning the terminals and dusting the sensor before replacement to no avail.

I'd try and get the codes read, as I was advised by my dealer that the AQS being faulty can bring the bus down that controls the heater flaps etc.

OH!, and the passenger heat would not heat, after replacing the unit, again normal function restored.

Thanks will try and get the codes read and may just take a punt.

Do you know the Volvo part number you got ? And what MY and engine do you have?

Though I suspect there may be more than one and it would be good to know which one to get for my April 2006 XC90 2.5 T SE.

Cheers

EDIT: Just noticed that you are selling lots of spares after selling the beast - and it looks to be a later model and diesel than mine

Mine was a MY09, and the 185BHP 5 cylinder lump (gosh I miss that car!.) I will post the part number when I get home as the box and the old one are in the garage.

FRF can advise ... they supplied mine.

AQS for my 2009MY was 31348901, cost was £79.63 + vat

Got it from FRF using the C3 code for the forums discount.

Best check, but I would think/guess all the post facelift cars use the same sensor.