Group 28 Engine Control Module (ECM) Diagnostic Trouble Codes (DTCs) SAE J1939 FMI Table 5 FMI SAE Text 0 Data valid but above normal operational range - Most severe level 1 Data valid but below normal operational range - Most severe level 2 Data erratic, intermittent or incorrect 3 Voltage above normal, or shorted to high source 4 Voltage below normal, or shorted to low source 5 Current below normal or open circuit 6 Current above normal or grounded circuit 7 Mechanical system not responding or out of adjustment 8 Abnormal frequency or pulse width or period 9 Abnormal update rate 10 Abnormal rate of change 11 Root cause not known 12 Bad intelligent device or component 13 Out of calibration 14 Special instructions 15 Data valid but above normal operating range - Least severe level 16 Data valid but above normal operating range - Moderately severe level 17 Data valid but below normal operating range - Least severe level 18 Data valid but below normal operating range - Moderately severe level 19 Received network data in error 20 Reserved for SAE assignment 21 Reserved for SAE assignment 22 Reserved for SAE assignment 23 Reserved for SAE assignment 24 Reserved for SAE assignment 25 Reserved for SAE assignment 26 Reserved for SAE assignment 27 Reserved for SAE assignment 28 Reserved for SAE assignment 29 Reserved for SAE assignment 30 Reserved for SAE assignment 31 Condition exists