CANbus Diagnostic Trouble Codes are a pair of numbers; The number of the suspicious parameter (SPN) and the failure.
Mode identifier (IGF). The SPN indicates the failure subsystem, and the FMI determines the type of failure.
Standard SPN codes are defined by SAE J1939-71. Not all standard codes are provided by the computer.
Manufacturers can add additional SPN codes beyond the codes specified in J1939-71.
51 Throttle Position
91 Accelerator Pedal Position
94 Fuel supply pressure
98 Engine oil level
100 Engine oil pressure
110 Engine Coolant Temperature
111 Coolant level
The FMI codes are defined by SAE J1939-71. Refer to the ECU documentation for proper interpretation of the FMI codes for a particular SPN.
0 Data valid but above normal operating range
1 Data is valid, but below normal operating range
2 These data are unstable, intermittent or incorrect
3 Voltage above normal or short circuit
4 Voltage below normal or short circuit
5 Current below normal or open circuit
6 Current above normal or earthed circuit
7 The mechanical system does not respond properly
8 Abnormal frequency, pulse duration or period
9 Abnormal data refresh rate
10 Anomalous rate of change of parameter data
11 The failure mode is not identified
12 Poor smart device or component
13 Due to calibration
14 Special instructions
15 Data is valid, but above normal operating range (least severe)
16 Data is valid, but above normal operating range (moderately heavy)
17 The data is valid, but below the normal operating range (the least serious)
18 The data is valid, but below the normal operating range (moderately heavy)
19 Received network data by mistake (for example, over the network)
Reserved in future for future firmware versions
31 Not available or condition does not exist