991 sudden lurching

[alphonso]

Hi all
I've got a strange niggle in that I'll be driving at around 40-50mph and the car suddenly pulls to the right for about 5 seconds then corrects itself. I have to hold the steering quite hard to keep it straight then I feel a swerve back on track. At first I thought it might be a gust of wind or grooves/ruts in the road but it's happening too many times now. The car is under warranty so I can take it in but wondered if anyone can shed any light on it. It might be somethign to do with the PDCC.
Has anyone else heard of or experienced this?
thanks
Al

[Rockster]

Can't imagine PDCC causing the vehicle to pull. Might cause it to tip to one side or the other if it somehow got triggered inadvertently. I'd think the PDCC controller would have some kind of back up to know this though and turn on a warning light.

But maybe not.

Are you sure the tires are not encountering some particularity bad road surface -- with pronounced depression where the many (and probably heavy) vehicles track over and over again? In both of my Porsches I've encountered a some sections of road that have had me pull the car off the road and check for a low tire the car's feel is so bad from what proves to be just horrible road surface.

[supersport]

Maybe the electric power steering has a mind of its own.

[Whitean3]

Have you checked tyre pressures/uneven tyre wear? This can drastically affect tramlining. Otherwise, it may well be something to do with the electric steering (of which I have zero experience)

[lukecollins]

I had a similar issue on my Audi which I think has the same type of pss, had a software update and its much better now. Found if it was placed it sport mode the problem
was less noticeable.

[alphonso]

Thanks guys and spot on regarding the tyres. I had a nail puncture about 3 months ago - it was near the outside wall and cheapest replacement was from Kwikfit who fitted an Aston Martin Pirelli P Zero by mistake - the OPC picked up on it when I took it in y'day. The AM tyre tread is the same as the Porsche and kwikfit completely bhed about changing it, but problem solved
Cheers all