Ross Brawn says his team must "work back and understand its problems" after Jenson Button could only finish in a distant seventh place in the Hungarian Grand Prix.
Brawn admitted that the BGP 001 was not only graining its tires but performing "differently" to three races ago when Button was dominant in Turkey.
"This is a problem we have got to try and solve because again we struggled with tire temperatures and graining in the race," Brawn told the BBC. "There were a couple of points where we had the tires on, we pushed hard and the laptimes started to come, but we just can't do them consistently at the moment. It's completely different to how it was at the beginning of the season.
"We have got to unravel, perhaps, what we have done in the last couple of races and understand if we have done something that has exacerbated the problem. Jenson was complaining about his tyres in the race again and it is very frustrating.
"We got away lightly today because obviously Sebastian [Vettel] didn't finish and Mark [Webber] was third so we've lost a bit of ground but not catastrophic so... Nice challenge that."
Asked if he thought the problems were related to the two updates the car has received so far this season, Brawn replied: "It seems to have changed from where we were three or four races ago. Monaco we didn't have a tyre problem, Turkey we didn't have a tire problem. We have now had three races where we are really struggling to get the tires to work.
"Obviously, other teams have gone forward and your comparisons change but we are getting problems that we never saw in the early races," he added. "But we have graining problems and other issues and we have got to work back and understand the problems."