Error Code Er Dh

My LGX25960ST LG refrigerator has an er dh error code. I have replaced the main pcb as well as the defrost sensor. The heater reads 37 ohms which means it is good. The freezer and the refrigerator are cooling up and I think it is defrosting fine cause there is no build-up but I still get the "er dh" code. What am I missing? Is there a specific orientation as far as the placement of the defrost sensor in reference to the evaporator or heater? I appreciate any help that would fix this problem.