What could have been the fault of my 1998 Toyota Camry when the dash board is showing (Check engine) ?

Question

The gear selector light doesnt indicate green square light when i select D- DRIVE but shown on the other gear when monitor on the dash booard.

thirdly the red indicator on the Automatic Gear itself always stop when it get to N-neutral but the gear handle move to a selected gear of choice & move smoothly.

Answer 1

i didnt really get your question but any engine warning lights need a garage to check the car is safe, what most manuals say unless you know where the circuits are to check fuse that controls the gearbox. which could have  a fault too. automatic gearsticks only shift when you have a foot on brake.

Answer 2

If dashboard is showing check engine, check the oil and water.