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Discussion Starter #1
Hi All,

The weather is getting better now and a working air condition would be nice.
When I bought the car I already noticed the air condition did not become cold but since the pipes under the hood where cold I assumed a refill of coolant should do the trick.

Today I had the air condition serviced: drained coolant and oil, removing moisture and perform leak test and fill it up again with coolant and oil including UV fluid for detecting possible leaks in the future.

Turns out coolant level was at the beginning 525 instead of 550 (gram?) so no leak but still the interior did not cool down after the air condition service. But again the pipes underneath the hood where freezing cold.

We checked the compressor, it was building up good pressure so the compressor and magnetic clutch is working.

That leaves only 1 thing left, one of the valve/actuator between the vaporizer and the rest of the system is not working.

Now the question is, which one.
Scanned the climate control ECU but no errors where present.

I found a picture from elearn which shows all the acutators.

My guess it would be one of these two:
N080 AIR DISTRIBUTION FLAP ACTUATOR
N081 MIXTURE FLAP ACTUATOR

Which one do you think it could be?

I already removed the glovebox and saw the space to work is very small so any help in pointing out the actuator which gives the problem would be appreciated.
 

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as an educated guess... N081

N080 would be the position sensor for the feet, dash vents, windscreen selection. before you get too involved with faulting sensors with no fault codes, im 99% sure there's a re-teaching procedure. may very well tell you in eLEARN or there could be a procedure in MES, if you wish to look further but i dont know for sure as ive never had to do it.
 

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Discussion Starter #3
N081 is indeed the actuator that controls the valve to get the cold air of the vaporizer or the warm air of the engine.
I did check MES and elearn for re-teaching procedure but did not found anything.

So I removed the N081 actuator and manually played with the valve and I had the feeling when its fully set to get the air of the vaporizer It seems to get a bit colder than before.

Not as cold as it should be I think, not sure if other 159 owners have the same experience?
Maybe the vaporizer is blocked by dirt? Seems unlikely since the dirt should be blocked by the interior filter.
I did put in a new interior filter with carbon, maybe its blocking the airflow to much?

Next I checked the actuator itself since the motor was getting really warm.

All gears where fine, it looks like a brushless electric motor and it uses a secondary winding for feedback.
Also I tried controlling it with MES but was not always responsive. The position indicator shown by MES was sometimes at 200% and it wouldn’t move.

Also when I stopped the car’s engine the actuator starts turning to a certain position after 30 seconds or so.
Sometimes the travel of the actuator was that much that it seems it was checking the end positions of the valve flap by stalling the actuator which could explain why it was getting really warm.

Since I couldn’t find anything wrong I installed back the actuator as following to ensure it was placed back correctly:
- I put the valve back manually in the cold position
- Connected the actuator back to the car but not connected the shaft to the valve
- Drive around with AC on and coldest setting.
- Stopped the car but leaf it running
- Connected MES and checked feedback of the actuator, which was now on 0% and was responsive to commands. Made sure to put it back at 0%
- Disconnected the actuator to ensure it does not move again when car’s engine is stopped
- Stop the car’s engine
- Installed it back to the valve.

The shaft is slotted (square profile) and I did fit.
Now when AC is on I have the same temperature as when the valve was controlled by hand.
So now I know for sure the actuator is in the correct position and not partly.

Next I will check how cold the air is with AC on using the procedure described in elearn.
Should be between 6-10°C.
 

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Discussion Starter #4
Tested it today.

Procedure listed in elearn says with ambient of 20°C it should be at 6-10°C internally with AC on after 5 minutes, fan at speed 3, measured at vent in the middle.
With ambient of 26°C I measured 15°C internally with AC on, fan at speed 3, measured at vent in the middle.

So it seems to be right for this type of car.
 

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im 99% sure there's a re-teaching procedure.
On the 147, and I daresay others, it's simply a matter of disconnecting the battery for 20mins, reconnecting and then leaving it for 5 minutes before turning the ignition key as the flaps (audibly) self-calibrate.
 
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