Cummins ISB4.5 CM2150 Fault Code: 477 PID: 444 SPN: 444 FMI: 1 Battery 2 Voltage – Data Valid but Below Normal Operating Range – Moderately Severe Level.

Posted by PerDiezel Solutions on January 20, 2026

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 keyswitch is in the ON position.

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 or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
-The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes
-The ECM will turn off the MIL after 3 consecutive trips where the diagnostic runs and passes.

Possible Causes
-Improper battery voltage setting in INSITE™ electronic service tool
-A damaged alternator causing low voltage
-A weak or damaged battery.

Cummins ISB4.5 CM2150 Fault Code: 471 PID: SPN: 98 FMI: 17 Engine Oil Level – Data Valid but Below Normal Operating Range – Least Severe Level.

Cummins ISB4.5 CM2150 Fault Code: 466 PID: SID 32 SPN: 1188 FMI: 4 Turbocharger 1 Wastegate Control Circuit – Voltage Below Normal or Shorted to Low Source.

Cummins ISB4.5 CM2150 Fault Code: 465 PID: SID 32 SPN: 1188 FMI: 3 Turbocharger 1 Wastegate Control Circuit – Voltage Above Normal or Shorted to High Source.

Cummins ISB4.5 CM2150 Fault Code: 452 PID: SPN: 157 FMI: 4 Injector Metering Rail 1 Pressure Sensor Circuit – Voltage Below Normal or Shorted to Low Source.

Cummins ISB4.5 CM2150 Fault Code: 451 PID: SPN: 157 FMI: 3 Injector Metering Rail 1 Pressure Sensor Circuit – Voltage Above Normal or Shorted to High Source.

WARNING!