ABS Fault

Hi all im hoping someone may be able to help me? Its MOT time and i need to get rid of the ABS light on my dashboard, ive done the blink test and is coming up with 2 - 8 which is no vaultage to the ABS valves, ive checked the wiring all looks fine, next is the relay under the passenger seat...Can relays just stop working? Is there any way of checking them or am i better just buying a new one? ABS pump kicks in as normal

thanks all

craig