Cummins ISM CM870 (2003-06) Fault Code: 319 PID: P251 SPN: 251 FMI: 2/2 Real-Time Clock Power Interrupt – Data Erratic, Intermittent, or Incorrect. Real-time clock lost power.

This fault indicates that the real-time clock in the ECM lost power. Possible causes for this fault are weak or damaged real-time clock battery, damaged wiring or connectors between the battery and ECM, or the engine is not equipped with a real-time clock battery and the vehicle battery power to the ECM is lost.

Possible repair:

1)Repair or replace the real-time clock battery.
2)Replace the engine harness.