hi i have a 2003 dodge caravan sxt 3.3l . she got 149 000 km on it . 2days a go the transmission wont shift up , i think it in 3 gear all the time but when i take off at the light or stop it feels like it shifting . when i get to 60km/h it doesn t shift up at all . i didint change any trany fluid but it look ok .