Hi! 

 

/cdn-cgi/image/format=auto,onerror=redirect,width=1920,height=1920,fit=scale-down/https://www.vwforum.com/attachments/20231001_101431-jpg.19220/

First post here so bare with me
Got a 2006 with a climatronic- not The knob kind but the digital one.
It cools just fine, heats up fine but the fan blower speeds up and slows down with a will of its own. This problem occurs regardless if i have it on auto,econ recirc or not. It also occurs regardless if i have it low or high/warm temp.
I already changed the resistor and the whole climatronic display unit.
When I do a self diagnostics it comes back with error code 4fa 02 wich i think is the recirculation flap motor. But if so, what does that have to do with the fan speeding up the slowing down?
Again my problem is that it (the ac) could be on lets say, bar 2 on fan speed, 21 c. No auto or specific direction as in regards to where ut blows air. It then frequently speeds up to bar 4-5 for maybe 10 seconds. The stops full. The back to bar 2.
Any tips would be extremly helpfull. I post here cause the climatronic unit is in more than just the Polo if im not mistaken.

Is that in a polo or another car?  Depending on the car, the recirculation flap mechanism isn't too bad to get to with the glovebox out. They sometimes just need a clean and lube. You might be able to hear if it's working or struggling from the passenger footwell  if you cycle it with the engine turned off and the fan on low. You can normally hear a gentle thud as the flap closes. It normally sounds like tapping a plastic coffee jar lid with your finger. And sounds of the flap repeatedly cycling would definitely indicate a problem.

 

On some VAG units, there's a temperature sensor in a little air intake behind one of the grills on the unit in the picture, sometimes with a fan to suck air in. These can get clogged up with dust giving some spurious readings. If you're blowing it out with an airline, keep the pressure set really low. 

Edited 4 November, 20232 yr by Yeti

On 04/11/2023 at 03:08, Yeti said:

Is that in a polo or another car?  Depending on the car, the recirculation flap mechanism isn't too bad to get to with the glovebox out. They sometimes just need a clean and lube. You might be able to hear if it's working or struggling from the passenger footwell  if you cycle it with the engine turned off and the fan on low. You can normally hear a gentle thud as the flap closes. It normally sounds like tapping a plastic coffee jar lid with your finger. And sounds of the flap repeatedly cycling would definitely indicate a problem.

 

On some VAG units, there's a temperature sensor in a little air intake behind one of the grills on the unit in the picture, sometimes with a fan to suck air in. These can get clogged up with dust giving some spurious readings. If you're blowing it out with an airline, keep the pressure set really low. 

Thx man posted in alot of different forums but very few replied.  Yes its a polo 06. I disconnected The whole flap engine and kept it open meaning all air from outside but The problem remains. It doesnt act up immidietly but after like 15 min of driving. Then The fan does this whole speeding up, going to zero then back to normal. Weird.you think the temp sensor is to blame? Thank you again for your reply.