Cummins ISX12 CM2250 (2010-12) Fault Code: 319 PID: 251 SPN: 251 FMI: 2 Real-Time Clock Power Interrupt- Data Erratic, Intermittent, or Incorrect

Circuit Description
Under ordinary operating conditions, the real-time clock in the Electronic Control Module (ECM) is powered by the vehicle’s batteries. If battery power to the ECM is lost, then the real-time clock will be powered by a battery in the engine harness (if equipped).

Component Location
The real-time clock battery is secured to the engine harness near the ECM.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes
The ECM detects that the real-time clock battery voltage is 3.3-VDC.

Action Taken When the Fault Code is Active
The ECM flashes the amber CHECK ENGINE light and/or illuminates the Malfunction Indicator Lamp (MIL) at initial key-on when the diagnostic runs and fails.
The real-time clock values in the ECM data will be incorrect.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE? electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
The ECM will turn off the flashing amber CHECK ENGINE lamp after the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
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 Cause:
1) Real-Time Clock Battery failure
2) Engine Harness
3) ECM calibration