Abs lights

[Roadcaptain]

I have a 53 1150 and last week it had a sticky front caliper, so I did some in and out with it and lubed it up getting it to move freely, passed the MOT now I have warning lights on. Triangle is solid and brake warning is slow flashing which indicates one systems has no ABS. Both brakes using servo fine, did manage to lock the back up just wondered if there is anything I can look at before Sherlock's opens on Tuesday. Keen to get it sorted as leaving for artic circle on the 10th. I have asked if anyone has a code read in the SW forum.
Could it be a dirty sensor if so what is best way to clean them?
Could I have damaged the front sensor when doing the caliper?
Is there a way to test sensors?

 

[oblertone]

Check the hand guard isn't fouling the lever and stopping a full return.

 

[Roadcaptain]

it's not