Cummins ISX12 CM2250 (2010-12) Fault Code: 477 PID: 444 SPN: 444 FMI: 18 Battery 2 Voltage- Data Valid But Below Normal Operating Range- Moderately Severe Level

Circuit Description
The aftertreatment diesel exhaust fluid controller communicates with the ECM and controls the heating, dosing, and purging of the aftertreatment diesel exhaust fluid system.

Component Location
The aftertreatment diesel exhaust fluid controller is installed on the vehicle by the OEM. Refer to the OEM service manual for component location.

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is running.

Conditions for Setting the Fault Codes
The aftertreatment diesel exhaust fluid controller detects that the battery supply voltage is lower than a threshold.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
Diesel exhaust fluid injection into the aftertreatment system is disabled.
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 battery voltage rises above 10-VDC and the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE lamp after the diagnostic runs and passes.
For On Board Diagnostic (OBD) engines, the ECM will turn off the MIL after 3 consecutive trips where the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk
Possible causes of this fault code include:

Improper battery voltage setting in INSITE? electronic service tool
A damaged alternator causing low voltage
A weak or damaged battery.
Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Possible Cause:
1) Loose Connections/ Terminals
2) Fuses
3) OEM harness
4) ECM calibration