Error code C242F on MB E500 2003



I had a garage change my break lines that were rusty. After the break line change, the car shows three errors: ABS error, ESP error and Service Break error. The fault code showing is C242F Rear Wheel speed sensor right, Test Wiring Plug Connection. What does the error code imply? Also, the car cleared the error code itself yesterday, it was gone this morning, only to come back in the evening. I can reset the error code and it will stay off for a while only to return, but with no apparent trigger. In other words, it comes back without anything evident that would trigger it, and in different times and distances. The breaks are just fine, but I can feel (it may be my imagination) that the suspension is more stiff. Cheers