How does it feel when PSM engages?

[PhoenixBlue]

No codes as far as I know.. he just sent me photos of the wiring that look like they were taped up by the previous owner (see pics)!

The ABS and PSM lights (but not engine) did come up recently, but an alternator change sorted that out - or at least both lights remain off.

Originally Posted by 986 Boxster

It could be a wheel speed sensor. Did your mechanic check for codes with Porsche OBD scanner? Check for codes first, it should tell you where the problem is. If it`s a wheel speed sensor the ABS light usually comes on, and some times even the engine light.

[986 Boxster]

That looks like it could the problem. But like I said before, you should have some codes coming up if it`s a wheel speed sensor or something else related to the PSM and ABS systems.
A regular OBD scanner can't read Porsche faults codes in the PSM and ABS modules. You need a Porsche code reader, like Durametric, etc.