I’ve got a 1997 F350 with a 73 diesel in it and the E4od automatic transmission. This transmission has about 5000 miles on a jasper replacement supposedly had 38 upgrades and the light is flashing on the gear shifter and it will not go into the low gears only in drive and will not shift. The range sensor has been replaced on the side of transmission... I’m wondering what else can be wrong? Only guess is coils inside transmission? Any knowledge out there? Or take it to a ford dealership?