Tachometer shows 5 but it's in park. X5 won't start. Any advice?

Check engine light is on when the key is on but scanner shows nothing.

Started the other day when driving through really bad weather, lotta rain/water on the road. It corrected itself by the time i got back to town but now it's showing 5 when I turn the car on, even though it is in park. I can move the gear shifter to anything and it still shows 5.