Today when I was driving my car's drive light started blinking and I put it in sport and in neutral but it was still blinking. I pulled in the nearest parking lot and turned it off and then turned it back on and the D light wasn't blinking but the engine light is still on. I've searched and read about it probably being the transmission, but what I didn't understand will changing the fluid most likely fix it or is it probably the sensor? By the way its an 07 automatic sport.

 

It can be line pressure solenoid.
To eleminate guessing use scanner and read the code