Flashing OD indicates an internal transmission problem. Hard shifting is generally associated with high line pressure caused by the PCM putting the tranny in limp home mode after an internal fault has been detected (slippage). OD light also flashes when the ATX fluid overheats, again caused by an internal tranny failure. Driving it this way will cost you more and more. Park it and fix it.
Typical failure is the bypass pass valve causing the TC to slip and overheat. But it is not the only cause of CD4E problems. Have it scanned and tested.
jeff
