check your oil level?
It is not supposed to be on when engine is running unless there is a problem.
Excessive blow-by (a tired engine) and/or the PCV system is not functioning correctly. Also, check the condition of the gasket under the oil fill cap.
When a check engine light comes on, it means that there are issues with the engine. It gets turned off when the person resolves the problem that caused it to turn on.
The filler is on the engine valve covers and marked. Do you know where the check engine oil stick is located? Don't go anywhere until you check the oil and find that filler. It is like a milk bottle top but larger.
The same way you turned it on
Use an OBD code scanner to find out why the computer has turned on the check engine light.
There is no filler cap for a transmission. to add fluid you must pour it down the dipstick tube. only check the level of the fluid with the engine idling at normal running temperature.
The "bulb check" feature of most cars work by all coming on momentarily as the key is turned to the "on" position before turning further to the start position, then go out if there are no problems after engine is started and running. Also on the "Check Engine" light will illuminate any time the key is in the "run" position but the engine is not running.
There is no filler cap for a transmission. to add fluid you must pour it down the dipstick tube. only check the level of the fluid with the engine idling at normal running temperature.
check coolent level
Try replacing your Oxygen sensors they are located on the catalytic converter. I had the same problem with my 94 Caprice and that turned out to be the problem.
Check the transmission dipstick from the filler plug. It's located at the rear of engine bay, passenger side.