driving at 50 mph, odometer suddenly dropped to 0 and stayed there. 5-10 seconds later, transmission suddenly downshifted and stayed there and was unable to move gear shift from D to 3. Got off Parkway, stopped vehicle, engine still running, I shifted into NEUTRAL, REVERSE and PARK (no problem). I then drove home very slowly ( not to damage the transmission ) by way of neighborhood streets. Next day on way to repair shop, everything suddenly began working perfectly for 5 minutes, THEN THE PROBLEM RETURNED for a few minutes, then again everything returned to normal. At the repair shop, a diagnostic reader connected to the vehicles' computer indicated a either the OUTPUT SPEED SENSOR or WIRING. Both were checked and only the OUTPUT SPEED SENSOR needed replacing. HAPPY DAYS ARE HERE AGAIN.
speedometer reads 0 until the next time you start the engine. It has never stopped while the engine is running.