Cummins X15 CM2450 X124B (2018 & Newer) Fault Code: 3338 PID: SPN: 5395 FMI: 18 Engine Idle Fuel Quantity- Data valid But Below Normal Operating Range- Moderately Severe Level

Circuit Description
The ECM uses diagnostic software to verify injector operation. During selected conditions, each injector is fired. The fueling quantity and timing are then compared to a specified threshold.

Component Location
The engine harness connects the ECM to the pass-through connector(s) that are located in the rocker housing. Internal injector harnesses are located under the valve cover and connect the injectors to the engine harness at the pass-through connector(s).

Conditions for Running the Diagnostics
This diagnostic runs continuously when the engine is operating at idle and PTO is not active.

Conditions for Setting the Fault Codes
The Engine Control Module (ECM) detected the idle fuel quantity was lower than expected.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE lamp and/or Malfunction Indicator Lamp (MIL) after the diagnostic fails on two consecutive trips.

Conditions for Clearing the Fault Code
To validate the repair, perform a key cycle, 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 amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
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.
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:

Malfunctioning fuel injectors

Possible Cause:
1) ECM calibration