My engine light has been coming on and going off for the last year. I seems to come n when I'm shifting the gears from reverse to drive. when the engine light comes on the "D" for drive doesn't show up when i shift from reverse. A box with a slash going threw it shows up in it's place.Usually, after a few minute the box and slash disappear and the "D" for drive appears again. This problem has gotten increasingly worse in the last few weeks and now the engine light isn't going off.