Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 6485 PID: SPN: 4375 FMI: 2/2 Aftertreatment 1 Diesel Exhaust Fluid Pump Drive Percentage - Data Erratic, Intermittent, Or Incorrect - EcuForce Truck (2024)

Lamp:
Amber

Reason:
The diesel exhaust fluid pressure sensor has reported a reading too high or low for the operating conditions.

Effect:
Possible reduced engine performance.

Circuit Description:
The diesel exhaust fluid dosing unit lines are responsible for transporting diesel exhaust fluid between the dosing unit, dosing valve, and diesel exhaust fluid tank.

Component Location:
There are three diesel exhaust fluid lines. One line is between the dosing unit and dosing valve, and the other two lines are between the dosing unit and the diesel exhaust fluid tank. These lines can be partially hidden from view by the SCR system and other vehicle components. Line routing will vary, based on the aftertreatment architecture and the OEM.

Conditions for Running the Diagnostics:
This diagnostic runs when the SCR system is trying to prime.

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected the aftertreatment diesel exhaust fluid pressure was less than a threshold.

Action Taken When the Fault Code is Active:
1. The ECM illuminates the amber check engine lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.
2. Engine torque will be severely reduced.
3. Vehicle speed will be limited to 8 km [5 mi] per hour after extended engine operation with the fault code active.

Conditions for Clearing the Fault Code:
1. To validate the repair, perform the “aftertreatment diesel exhaust fluid system leak test” found under “ECM diagnostic tests” in the recommended diagnostic tool or equivalent.
2. The fault code status displayed by the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
3. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs and passes.
4. For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5. The “reset all faults” command in the recommended diagnostic tool or equivalent 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:
1. Low aftertreatment diesel exhaust fluid level in the diesel exhaust fluid tank.
2. The line heaters are not successfully thawing the frozen diesel exhaust fluid.
3. The diesel exhaust fluid pressure line between the dosing unit and dosing valve is kinked, broken, or disconnected.
4. The diesel exhaust fluid suction line between the diesel exhaust fluid tank and the dosing unit is kinked, broken, or disconnected.
5. Malfunctioning diesel exhaust fluid dosing unit.
6. The diesel exhaust fluid suction and return lines between the dosing unit and diesel exhaust fluid tank are reversed.
7. Debris from the diesel exhaust fluid tank. If debris is found in the diesel exhaust fluid tank, clean the diesel exhaust fluid tank thoroughly and fill with certified diesel exhaust fluid.

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