Hi, i have a 2002 3.3 l V6 caravan that started having surges in shifts between 1st and second. then it stuck in what seemed like 2nd (4000 rpm at 40 kph) i took it to a tranny shop that had replaced my original blown tranny with a 2001 model that i bought online. that replacement has worked fine for 8 months. so the tranny guy replaces my alternator with the one from the 2001 parts van i bought?! being frugal i thought great. but the sppedometer was flipped. i reset it and for a day it worked fine. the surges started getting worse and the speedometer was flipping out. i replaced the Transmission speed sensor and the transmission output sensor as i read on line that these are commom problems. now the van is in limp mode and the speedometer doesnt work. right now i have pulled the IOD fuse to see if that helps. how do i check for codes using the odometer button?