only dealers and independents who have the very expensive subscription several thousands i believe can do software up dates clone vida cannot do it. the aqs sensor is the most ignored fault on this platform of cars due to the price of a replacement unit for what it dose its just not worth paying for this on a 20yr old car.. any s/h units are more than likely to be faulty keep working through your list to end up with a great car

I've never seen a P2 Volvo without an AQS fault

if it's not got AQS and alarm service required faults is it really a 20 year old Volvo?

Haha...its an '06 plate and about to click over 140k so not far off. I havent yet rechecked for AQS fault but will this week.

But with my intent to do an injector service, i got to wondering how coked up the inlet valves might be and whether an induction service might be of benefit ie remove inlet manifold and decarbonize inlet valves). Do these cars suffer from bad carbon build up on the valves? Or is there yet more magic in a Volvo where its unlikely?

you beat me to this fact. iv never seen one either ha ha.:eek:

i have 250k on mine and have had no problems with valves coking up use good fuel and regular oil changes including transmission fluid if its an auto sit back and drive and enjoy the car dont go looking for problems the volvo mark is very reliable if maintained .:regular_smile:ps you can not service injectors the either work or not you may cause yourself more problems by messing with the fuel system:regular_smile:

Not sure but possibly a poor design is the reason for failure, not worth spending up to £350 (eBay prices) on one just for it to throw a code in a few months time again when it breaks.

Has anyone priced one from Volvo?

I've read there is a VW sensor that fits and costs around £20-£30, if that was the case I would go down that route but as I don't have any proof it actually works I will live with my knackered AQS for the time being

Does it make any noticeable difference to the running of the car or AC or anything

I'm assuming mine just doesn't have one then because it doesn't come up as faulty

I do have the ubiquitous ddm and pdm faults though, that's pretty much standard as well as far as I can tell from looking it up in a number of places (again, everything works perfectly)

ita a micro filter that closes a flap to stop any bad smelling air into the cabin when its working.

Does your car have the MAN / AUT button for the AC recirculation? The sensor opens and closes the recirc when it's on AUT and it feels outside is "dirty".

I have taken a punt on a VW one from eBAY that is meant to work on 2002 to pre-facelift cars. "Air Quality Sensor Fit For VW CC Golf Tiguan Passat Caddy Amarok 5QJ907643"

https://www.swedespeed.com/threads/c...d-p2rs.409305/