spn fmi description 28 3 % accel pos3 volt above norm or short high ... spn fmi description 970 31 ext aux eng shutdown switch active 971 31 eng derate switch activated 1041 2 start signal missing 1041 3 start signal always active ...SPN 1214 DM25_ExpFFSPN 6 I NNNNNN 0 - 524287 FF SPN Occurrence Count 1216 DM25_Occurrence 3 I NN 0-127 FF FMI 1215 DM25_FMI 2 I NN 0-31 Expanded FF SPN Value 1545 DM25_ExpFFSPNVal 50 S NA NA Monitor Performance Ratio DM20 49664 Monitor vs. operation rate Ignition Cycle Counter