Hello, new to this forum but I belong to several others as I like to help my friends out when I can. A 2013 Focus shows a DTC code P07A3, "Transmission Friction Element A Stuck On". The car begins to bog down and has no power when the trans shifts to 2nd gear. My research showed that there may be a problem with the ground wire of the negative terminal of the battery. I sanded the mounting tab on the left front shock tower, sanded the cable tab and cleaned the bolt. Then went back and cleared the code. The car now runs good but I don't know yet if the problem was solved. Does anyone know if this has any other fixes I should know about and is it something that I can fix without going to the dealer? Any advise is greatly appreciated. Thanks.