Well I hate to give you the bad news. The code C1110 is a ABS control unit code. Let me explain the situation to you so you can understand it properly. Your local repair shop is most likely not aware of this problem so it was not repaired properly.
There are drains in the rear knuckles, that when clogged can cause the ABS pick up ring on the the wheel bearing to build up rust which narrows the gap for the readings on the ABS sensor. Once the rust gets to high, the sensor actually scraps on the rust and shorts it out. Once this happens, some times you get wierd and erratic ABS activations when braking. Then then next thing that happens, is the sensor shorts out the ABS control unit and can cause the code C1110. Once this happens, the ABS control unit will need to be replaced as well as both rear ABS sensors. Then you will also need to take off the rear hubs and clean the pick up rings. If they can not be cleaned then the hub assembly will need to be replaced. Then you will need to remove the rear E-Brake
shoes and where the clog happens in the knuckle, it will need to be grinded down and opened up a little wider so the clog will not happen again.
This is the reason you are having ABS issues, and what is involved to repair this. This is not a cheap repair and I am am sure your local repair shop was not aware of this. Hopefully the new ABS sensor is not damaged due to the rust on the Hub, other wise the new sensor would need to be replaced again.
If you have any more questions on this, please feel free to ask. Thanks Jay!