Mercedes Glk 350 ABS issue, cannot get the lights off the dash

I replaced all the brakes and new wear pad sensors. This took care of the brake pad wear error on the dash as that's now gone. My code reader told me the right rear speed sensor was gone so I replaced it, cleared the code then took the car out with a clear dash no lights. I got about 50 feet and the lights all came on again, Ran the code reader again which then told me the left rear is an issue. I replaced the left rear speed sensor cleared all the codes and had a nice clean dah with no lights. I drove 50 feet and it xmas again the dash is all lit up. I run the code reader again and it tells me D40C Right rear wheel speed sensor, DB40B Left rear wheel speed sensor. Not sure what to do next to figure out whats on the go with this car. Anyone has any suggestions please let me know currently the car is not drivable as its in limp mode.

Ok fearing I may of had two bad (new) sensors and they were the cheap ones from Rockauto I went to NAPA and bout the expensive ones. Installed them and still same issue. I then took the time to measure the resistance of the new expensive ones and compared that to the new cheap ones and it was exactly the same. I then connected my muitmeter to the plug in for the sensor as in where the sensor harness plugs into the car to see if there was any power there and I get 11 volts on both sides so I am now assuming there is no issue there. I then connected the multimeter to the sensor plug with it installing in the hole for the sensor and then spun the wheel but I get no signal or voltage from either wheel. So now I am wondering my next step...… Please guys anyone has some help here it would be greatly appreciated