Good evening, I have a rack that I service. Have been for 6 or 7 years and for the most part it works pretty well. It was just upgraded to a newer computor system . Lately, It has been logging an error code that it has failed to pump down. I am asking for guidance here, would it be the suction "sensor" that tells the computor it has reached the predetermined cut out set point or the low pressure cut out control located on one of the 5 compressors? or possibly none of the above? Thank you in advance