It is the orange check engine light, right next to the maintenance light

 

If that's the case then any decent code reader should be able to pull the codes (and there will be codes).

 

Code reader shows no codes current or pending. Starting to suspect the PCM. my experiences in the past have been when electrical makes you pull your hair out and nothing makes sense it is the computer.....lol

 

Electrical problems that make no sense are maybe more likely from bad grounds. (But bad PCMs aren't unheard of either.)

Also, there's about 4 different data protocols for OBD-2 and some of the inexpensive code readers can't read all of them.

Still, the behavior of the lamp to flash for several seconds then stay off is what the service reminder lamp should do. The actual check-engine light should stay on to indicate a fault.