A610 CAN fault volvo C30
 

Hey people, I just bought a Volvo C30 1.6D.

Unfortunately on the way home a warning light saying "engine service urgent" popped up. So plugged it into a mates diagnostic reader and it came up with; A610 CAN fault. Communication fail with Fuel additive system, fault in CAN communication.

Can anyone tell me what this is or is likely to be? Also how expensive/awkward is it to fix?

Cheers.