Cool is correct, it seems some vehicles produced between Jan and Apr 92 had a bad push button unit, it applied to vehicles with the charcoal filter. Kammerer were bad, Bosh were ok. As long as you are checking, is the circulating pump (REST) possibly running, the PSE also provides vacuum when the engine is not running. It is not on a switched circuit, and could be replenishing reseroirs for either the P+ side for lumbars or P- for vacuum I have fooled with it and it is possible to change flap positions with the ignition off I think. There seem to be a lot of leads but only one answer I guess