Since I replaced the PSE pump just in the last year, and all other functions of the PSE closure assist are working correctly, I’m leaning towards a vacuum leak in the climate control system – as KenP suggested. I just reviewed the procedure for testing the “vacuum valve block” (front passenger footwell ), valve block (behind the glove box) and vacuum reservoir (passenger firewall).
Wow.. this is a complicated system!
Just a side note… After clearing AC Diag codes (Special thanks to Jim F for posting the procedure on his website.) I continue to get E0 76-77 indicating a Heater Supply Unit circulation pump overload. Since my current problem doesn’t involve a lack of heat (only A/C) I’m going to review this issue at another time.
Has anyone performed the “Individual Flap Test” via A/C pushbutton control? The procedure doesn’t look clear.
I'll try lubing the 'lubing' the bearings on the blow motor in an attempt to quiet the "whining noise" too!
Geeze! Never a dull moment for W140 owners....
Thanks!