My brake light warning light came on yday on my xf 3.0 does anybody know if these are front or rear brakes as I'm new to jaguars as previous car was 5 series bmw . 

Any help would be appreciated .

Welcome to the club, Dominic.

Was the warning light red?  Or was it the ABS warning?

If it was Red, my handbook indicates that you will need a bit of expertise.

If it was amber, you could look at the brake fluid level.

If was ABS the brakes will operate OK but will not have the ABS assistance.

Other members with more expert knowledge than me will assist.

Regards,

Peter.

Thanks for you advice , had a look this morning took front passenger side and rear drovers side wheel off and found brake wear sensor was fraid  joined wires back together  and all is good

Thanks Dom 

I am told they are diagonal opposed I.e. one wear sensor on ns or os at front and on other side at the rear. I don't belive you can tell which is worn but generally rears are easier to look at through spokes in alloys.

There's one on the front & one on the rear. Plastic covered sensor leads that wear through and will earth to the disc at about when the pads are only approximately two 3rds worn! Usually the rears wear 1st on an XF. If taken to a main dealers your end-up with an eye watering bill! Consisting of : Discs, pads, sensor & brake fluid change. Jaguar OME brake pads & disc's are not the best available "The discs wear fast & the pads dusty" plus they don't come under warrantee.  After market sensors can be purchased a 3rd cheaper than they can from Jaguar. I my self use Mintex discs and EBC yellow pads. Your find that most aftermarket pads won't have the cut-out on the metal backing plate for the sensor, Which is easy to solve and takes 2 mins with a small hand grinder to cut a 'U' out. There's nothing special about replacing Jaguar brakes '30 mins a corner' and can be done with a standard tool kit & trolley jack + if the rears need doing your need a piston winding in tool or just purchase your self quality UK manufactured parts from a reputable supplier? (As that's the big mark-up in cost) And take it any independent mechanic.