Car won't start.

No, it was not turning over at all before I put the temporary ground,after temp ground was installed car was running but was still having issues like the car telling me (vehicle not in park) and (system memory disabled. Check engine light was on then, but assumed it was a previous code that it was having. Should have checked then to see if i was getting p0685 then. But car ran for two weeks but stalled a few times in the meanwhile.