Mine has just come on too. From previous experience, if the warning light comes on, its time to replace pads and maybe discs (i usually do both at the same time) more or less straight away. The sensor is probably shot too so will need replacing (one at the front and one at the back).
The light should disappear once the sensor has been changed, no need for INPA, etc.
I've price some Brembo discs and pads and a sensor for the front at £130 all in from GSF. This is through a trade account, mind.
