Ian Salisbury took three more wickets to take his haul in the match to five with the other wicket falling to Neil Carter who removed Ackerman who was on 199.
Leicestershire closed on 432 and in reply,Warwicks were 17-0 in a rain affected match at the close
The rain also affected the Test Match at Edgbaston. South Africa moved on to 256-6.
Former Warwickshire man Paul Harris added 77 runs along with McKenzie before he was out from the bowling of Ryan Sidebottom.