MBE 900 DDEC VI Troubleshooting – Section 79.1 SPN 986/FMI 9

Section 79.1
SPN 986/FMI 9

This fault is typically the J1939 CM1 message is missing.‪

Section 79.1.1
Missing J1939 CM1 Message Check

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 step 2 .
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.