My wife has a 2012 focus titanium. She left the lights on the other day and the battery died. She had someone help her beacuse I wasn’t around and they hooked the cables up backwards and now it won’t start. I have power everywhere in the car. All fuses are good It blew the ecu fuse. And I replaced it. . All fuse links are good. I get in pressing the start button. And everything comes on like it’s going to start. Then I get “ engine fault service now”. Any ideas what it could be? Or what to even do to try and get it fixed?