Ford isn’t having much luck having its hybrid vehicles.

After complaints that Ford’s hybrids couldn’t hit their stated EPA mileage figures, Ford is already facing a lawsuit that accuses it of infringing on technology patents in the hybrid vehicles, although don’t get us wrong, they’re selling well.

Bloomberg reports that Ford is being sued by Paice LLC, a Baltimore-based engineering company devoted to hybrid technology.

Ford and Paice met more than 100 times between 1999 and 2004 to develop a hybrid system that would increase gas mileage without losing performance.

That Ford’s hybrid system now relies heavily on hybrid technology learned from Paice, even though the two companies apparently struck a licensing deal back in 2010.

The complaint does note that Paice had provided to license its technology to Ford for $150 back in 1999, although there’s no set amount that Paice is seeking from Ford in the lawsuit.

If such an amount was commanded now, it could stand to lose quite a lot. Last year, Ford’s hybrid and electrified vehicle sales topped 85,919, greater than double its figures from the previous year, of 33,476 sales.

Ford had tried to preempt the latest lawsuit, filing a complaint in December to get a ruling that Paice couldn’t file a complaint, under the terms of the companies’ 2010 agreement.

Paice has previously won a lawsuit against Japanese automaker Toyota for patent infringement on hybrid technology.

It won a trial back in 2005, the companies finally settling in 2010 just before another trial started that could have observed Toyota banned from importing affected vehicles.

As part of the current Ford lawsuit, Paice says that Ford was sharing its technology with Toyota when Ford was working on hybrid technology together with the Japanese company in the late 90s and early 2000s.

Hyundai and Kia are also pending infringement complaints from Paice.