DD15 Troubleshooting – Section 40.1 SPN 523/FMI 19

Section 40.1
SPN 523/FMI 19

This fault is typically the transmission current gear signal is erratic.‪

Check as follows:‪

1. Check for multiple codes:
   1. If CPC SPN 168/FMI 0/14/18 (Battery Voltage) are present troubleshoot these first.
   2. If MCM SPN 625/FMI 9 is present, troubleshoot and repair the CAN line.
   3. If only a “J1939 Error” fault is present, go to the next step.
2. Has the CPC been recently reprogrammed?
   1. If yes, check the proper configuration of the CPC.
   2. If no, connect ServiceLink to determine which modules are configured for the vehicle and their communication status. Once this is done, follow the appropriate module communication troubleshooting procedures for the affected module.