pressure sensor signal implausible

[911_Turbo_AZ]

I have a 2001 911 turbo (20k miles) that's throwing off a strange code. PSM 4460 pressure sensor signal implausible. Nothing is stored in memory so the dealership can't determine the problem. When you turn the car off the error clears and the car is fine. Then at random intervals it will go off again. When it does it disables the PSM system and ABS. Has anybody has expirence with this problem before?

Thanks,
Mike