SAE (Society of Automobile Engineers) has developed standard lists for Diagnostic Trouble Codes (DTC)

Under the J1939 Standard there is a list of SPN (Suspect Parameter Number) Codes. Furthermore they have developed a Failure Mode Identifier (FMI) number for more information. THESE CODES WILL APPEAR ON YOUR MURPHY DISPLAY SCREEN FOR INSTANT DIAGNOSTICS.

SPN

Suspect Parameter Numbers (SPN Codes)

FMI

Failure Mode Identifier (FMI Codes)