I have a 1995 Mercedes Benz C220 with 80,000 miles. The check engine light is always on for a transmission down shift cable issue. The issue is my car's transmission does not shift smoothly from low to high gears but after a quick accelerated start the car drives smoothly but the engine light always stays on. This all happened when the old worn out transmission down shift cable was replaced with a new one which has been checked again when this problem surfaced. How can I get the problem resolved? Appreciate your help as I have spent enough to try to get this problem fixed.