QuestionHi. have an -99 Elantra (112k) with an auto transmission. No check engine light. Did a little preventive maintenance and dropped the pan, cleaned out everything, checked magnets plus changed the transmission filter. New oil. Runs good except will not go into overdrive...? Seems to shift fine through the lower gears, including kickdown. There's a little pushbutton on the gear selector, that you can select O/D, or not and as far as I remember, you could see the selection somewhere near the speedometer, but not any more? Electrical problem???
AnswerThis problem is electrical in nature. The overdrive switch works by switching power between the transmission control module (TCM) and the O/D OFF indicator in the cluster. When power is applied to the TCM, overdrive is enabled; when applied to the indicator, overdrive is inhibited.
First, check to see whether other indicators in the dash work-- oil pressure, check engine lamp, brake warning lamp, etc. If not, the fuse is probably blown. If they work normally, you know the fuse is okay, meaning that the problem is most likely with the overdrive switch itself.
