Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 5867 PID: SPN: 520953 FMI: 4/4 Aftertreatment Diesel Exhaust Fluid Dosing Unit Relay Feedback – Voltage Below Normal or Shorted to Low Source

Lamp:
Amber

Reason:
A short to ground has been detected on the diesel exhaust fluid dosing unit relay feedback signal.

Effect:
Possible reduced engine performance.

Circuit Description:
The aftertreatment diesel exhaust fluid dosing unit performs many functions, one of which is to generate adequate diesel exhaust fluid pressure in the lines, using a pump, to allow for dosing. The ECM provides a battery voltage supply and a ground to the diesel exhaust fluid dosing unit. The ECM also supplies a signal to the dosing unit to control the diesel exhaust fluid output. This signal changes, based on the diesel exhaust fluid pressure being commanded.

Component Location:
The aftertreatment diesel exhaust fluid dosing unit location is Original Equipment Manufacturer (OEM) dependent.

Conditions for Running the Diagnostics:
This diagnostic runs when the aftertreatment diesel exhaust fluid dosing unit is commanded ON.

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected voltage below a calibrated value on the pump relay feedback circuit when the dosing valve was commanded ON.

Action Taken When the Fault Code is Active:
1. The ECM illuminates the amber check engine lamp immediately when the diagnostic runs and fails.
2. Engine torque will be severely reduced if the engine is operated for an extended period of time with this fault active.

Conditions for Clearing the Fault Code:
1. To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs and passes.
3. The fault code status displayed by the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
4. The “reset all faults” command in the recommended diagnostic tool or equivalent can be used to clear active and inactive faults.

Shop Talk:
Possible causes of this fault code include:
1. A short circuit to ground in the OEM harness.
2. An open feedback signal circuit.