Thanks for the diagnosis and the vote of confidence, Haasman!

Can anyone provide insights into replacing the transmission modulator? (I did a cursory ShopForum search and didn't see any specific instructions.)

Specifically, do I need to drain the torque converter and pan before this R&R? Is it a "plug-and-play" swap, or will special tools be required?

(It looks rather straightforward and simple; but I'd appreciate confirmation of this before I dig-in!)

__________________
Eric

1991 560SEL-Euro (214,000 miles)
1989 420SEL (Retired from daily use at 325,000 miles; Use as donor vehicle)