ifts . ▁Although ▁five ▁of ▁the ▁six ▁r ati os ▁were ▁used , ▁Ch rys ler ▁decided ▁to ▁call ▁it ▁a ▁" 4 - speed ▁automatic ". ▁For ▁MY ▁ 2 0 0 1 , ▁the ▁programming ▁was ▁changed ▁to ▁make ▁use ▁of ▁all ▁six ▁r ati os . ▁R ather ▁than ▁have ▁six ▁forward ▁g ears , ▁the ▁transmission ▁was ▁program med ▁to ▁act ▁as ▁a ▁five - speed ▁with ▁the ▁alternate ▁second ▁g ear ▁for ▁down sh ifts . ▁The ▁r pm ▁at ▁ ▁on ▁a ▁ 5 4 5 R FE ▁is ▁ 2 0 0 0 ▁r pm , ▁ 2 0 0 ▁r pm ▁less ▁than ▁the ▁ 4 5 R FE ▁programming . ▁ 1 9 9 9 ▁and ▁ 2 0 0 0 ▁model ▁year ▁W J ▁own ers ▁can ▁have ▁their ▁ 4 5 R FE ▁transmission ' s ▁programming ▁flash ed ▁to ▁enable ▁the ▁extra ▁g ear ▁as ▁both ▁transm issions ▁are ▁phys ically ▁the ▁same . ▁( M ust ▁purchase ▁new ▁PC M ▁and ▁A BS ▁module ▁and ▁program ▁them ▁with ▁a ▁fake ▁V IN ▁to ▁make ▁this ▁work .) ▁The ▁ 4 2 RE ▁ 4 - speed ▁automatic ▁remained ▁the ▁transmission ▁for ▁the ▁In line ▁ 6 ▁engine . ▁It ▁had ▁slight ▁changes ▁from ▁the ▁previous ▁model ▁Grand ▁Ch ero kee . ▁ ▁The ▁interior ▁was ▁also ▁completely ▁red es igned . ▁The ▁red es ign ▁allowed ▁for ▁larger ▁rear ▁doors , ▁and ▁more ▁space ▁for ▁rear ▁passengers . ▁Control s