There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.
With a scan tool
the check engine light is blinking and my 03 Nissan exterra is running rough
No. It is illegal, will cause a check engine light and running problems.No. It is illegal, will cause a check engine light and running problems.
check the battery with voltmeter without the engine running then check with it running if voltage is higher it is working
Running out of gas my certainly be a cause for the check engine light to come on. It could also be an assortment of other issues.
Check the brake fluid...
No, check it after the engine has not been running for at least 15 minutes.
Answer There is a dip stick at the back of the engine. Start your engine first, let it run and check your transmission oil level. You only check transmission oil levels when the engine is running, other oil levels have to be checked when the engine is warm to hot but not running.
Simple answer, nope nope nope
No
If you are sure that all the wiring is ok, then check the fuel.
Your owner's manual will list this. If you do not have one then change them at the first sign of the engine running badly, check engine light on, fuel mileage dropping, or at 100,000 miles, whichever comes first.