Hey guys i have a 2006 Chevy Silverado 5.3l Hybrid and for some reason the battery light is on with a battery not charging message.. we found out that the hybrid control module is low on fluid and i need to know what fluid it is. I've called the dealer but they dont know either or dont wanna tell me.. ill attach a picture so u guys can see what part im talking about. this fluid is some kind of transparent gas, it evaporates real quickly.. if anyone know what fluid it takes please let me know.. thanks

the attachment picture is the part where the fluid is located.