A new motion for sanctions is pending in a contentious case against Ford Motor Co. that ended in a mistrial last month.

Lawyers for the surviving sons of Melvin and Voncile Hill, Kim and Adam, have asked Gwinnett County State Court Judge Shawn Bratton to punish Ford by excluding the company’s defense on key issues. Mainly the Hills are asking the judge to make Ford admit that its F-250 pickup roof was weak and defective, that the company knew it and did nothing and that a caving-in roof killed Melvin and Voncile in a rollover crash that could have been survived otherwise. That would leave Ford arguing mainly over damages when the case goes to trial again.