Does anyone have any ideas what might cause a Mercedes 722.6, in this case in a 2006 E55 AMG, transmission to refuse to coast? The problem surfaced a couple weeks ago in the middle of a long drive. Basically, the transmission wants to stay in lockup mode nearly all of the time. It shifts mostly normally, although occasionally there have been some rather jolting shifts, but mostly it just will no let go of lockup, behaving somewhat like a manual transmission would. It also occasionally wants to hold on to a lower gear than it should.
I have already replaced the conductor plate, plug (which was leaking slightly), and the TCC solenoid, but this did not correct the problem.
Any ideas on this one?