Yaris; SRS light on, horn not working, after steering rack just replaced

[El_Barto]

Hello all, Any wise counsel on this little chestnut? Today my gf's '03 Yaris had the steering rack replaced. And what a great drive it is now. Trouble is I was back to the garage in under a minute when I saw that the SRS warning light was now glowing at me. I have to take it back in tomorrow when they'll have acquired another diagnostic computer - it's not a Toyota specialist garage and the ones they have weren't being much help. On the way home I had a Sherlock thought an tried the horn. Not working! So this pretty much settles that the electrics to the steering wheel are disconnected in some way, physically or electronically, and the SRS light's on because the steering wheel airbag isn't showing present and correct to the car's computer. Here then is my question - the steering wheel wasn't removed during the rack change process, so what and where might the trouble be? Surely the work to replace the rack doesn' t come anywhere near the steering wheel's wiring? Do you suspect something physically damaged? Or can a resettable electronic condition also disable the horn circuit as well as the steering wheel airbag? All the best for now and ta for any insights, John