Disc system fault
That's disc not discussion
Check the battery to make sure it has 12 Volts a weak battery will throw codes. You may have a bad connection, or bad cable.
Check your pads for proper thickness. You don't say what the mileage is on the car but it may be needing new pads.
Looking for a Used X-TYPE in your area?
CarGurus has 467 nationwide X-TYPE listings starting at $2,000.
Search Jaguar X-TYPE Questions
Jaguar X-TYPE Experts