M111 Recirculating air flap. Where are settings stored ?

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Active Member
Mar 1, 2010
Hi. I have a problem with my recirculating air flap. Car throws a fault code every week or so (happens on 1st start up in the morning - car jerks a bit when starting up) and the car idle becomes lumpy and the throttle goes off, in the sense you need more throttle to get same power - car feels less powerful (W208 CLK230K 2001 btw).

Fault codes thrown up are P0101, P200B, and P2039 - also P2009 and P2020 very occasionally.

My manual recalibrating the recirculating air flap and erasing the fault code makes everything OK again (car does not jerk starting up and idle is fine, throttle is sharp)....... for about another week.

To my untutored mind , it appears that the recirculating air flap settings seem to "run" (change for the worse) after a while (1 week on average).

Can anyone tell me where these setting are stored ? The ECU perhaps ? Or on the Recirculating Air Flap component itself ?

Thanks in advance
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My only comment is that there seems to be quite a bit of oil vapour floating around in that system. As engines wear things tend to get worse leading to things getting gummed up. Have you had a look at the throttle body throat/ butterfly plate for example?
Yes. They've been taken out and cleaned before with throttle cleaner.

Are throttle bodies and recirculating air valve bodies prone to failure ?

I've opened them up to clean and they seem very low electronic, high mechanical.

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