Had the hdc fault, transmission fault and lowered susspension fault come on around 5 times today, after turning the car off and waiting a few mins everything goes back to normal,
Only thing I have done to the car today is change the brake/ rear light bulbs to Led ones, I'm hoping its linked somehow to the bulbs?
Anybody had any experience of this ?

Did you use CANBUS LEDs? The system will throw up errors if the brake bulbs are blown (or appear to be to the car). Easiest way to check is to stick the old bulbs back in (assuming you changed them before they'd blown). If the errors go then you know the LEDs aren't suitable.

Sadly, not all CANBUS LEDs or bulbs are equal in the eyes of the RRS...  2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Thanks for the reply,
No idea if the LEDs were canbus just an impulse e bay buy as one of my brake lights was out,
Just bought some standard P21 5W so ram long life ones of the net, hopefully fingers crossed it will resolve it, never would have thought some cheap LEDs would cause such a problem.

The problem is caused by the fact that HDC is hardwired in to the brake system - it activates the brake lights when it operates so if a bulb is blown etc. the system senses a fault and so reduces functionality. HDC is part of the Terrain Response system which also controls how the transmission and suspension works. You can get a cascade failure caused by a simple initial problem. It does have the beneficial effect of protecting you and the vehicle from doing damage because of a problem somewhere. The downside is that it doesn't discriminate a blown bulb from something more serious.

It's the sort of issue that gives the marque a bad name for electrical reliability although it's not that serious really. Compared to some of the mechanical issues that raise their heads...

Having said that, if you do the bulbs and it still isn't happy then you'll need to check for error codes. There may be something else causing the problem. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed