Checking this old but nice topic about our car's ACD, since I have been wondering the set up going on with the Evo I got.

Then I saw this...
Isn't it all CT9A Evos which include the 7 uses Active Center Differential aka ACD? I think its even the first Evo to use that technology.

 

What country are you in? In USA 03-04 Evos did not come with the ACD only the viscous coupling. ACD was introduced in 2005 for USDM Evo's.

 

Oh yeah I failed to mention that. Was referring to what jrainwater posted about the 7, which unlike the early usdm 8, all have ACD regardless of market.