When entering the engineering test code on the dashboard is there information what the codes mean. I have DTC NONE, OIL L, and battery volt 11.8 although the battery was on charge overnight 2 days ago.

 

Ignore the codes in ETM. They are years out of date and unless you use special software they never clear.

11.8 is a dead battery. Might recover but don't be too hopeful. If it's just dead then replace but be aware you may have a current drain - see the many threads about those.