PCS - pre collision system

[Fester37]

Hey all, Started this topic as I could find one about this. I've just got myself my first lexus, it's a 2005 GS430. unsure of the trim level etc but it runs perfectly, but with one small issue, the pcs error (fault). I have seen around the web that it's a common fault and cleaning etc can fix. I havent managed to get rid of it so far but I have noticed it only comes on after sitting at 70-80mph on the motorway so I'm assuming cleaning isn't the issue. It also doesnt happen often either but what i would likt to know is, can I replace it and where to find one. any assisstance on this topic will be very much appreciated.

My end goal here is to have it fixed or de activated (any way so I can use the cruise control again as it knock it off when it comes up).