The 210 shares one aspect of the older systems - vacuum actuation of the various flaps in the climate control system. This is driven from a "harmonica" valve behind the glove box.

If you lose vacuum, you will default to fail safe mode - defrost flaps open.

The source of the vacuum is the vacuum pump in the engine. On the vacuum label under the hood, look for the line that says "other consumers". The only "other consumer' in the 210 is the climate control system. The door locks and rear headrest dump control are from the PSE pump in a 210.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech