Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 3718 PID: SPN: 3216 FMI: 13/13 Aftertreatment 1 Intake NOx – Out of Calibration

Lamp:
Amber

Reason:
A nominal system voltage mismatch has been detected by the aftertreatment intake NOx sensor.

Effect:
None on performance.

Circuit Description:
The aftertreatment intake NOx (Nitrogen Oxides) sensor is a smart device and communicates with the Engine Control Module (ECM) via the J1939 data link. The aftertreatment intake NOx sensor performs internal diagnostics and reports malfunctions back to the primary ECM using the J1939 data link. The NOx sensor is permanently attached to the NOx control module. They are serviced as a single component and can not be replaced individually. The aftertreatment intake NOx sensor is used to measure the NOx emissions at the intake of the aftertreatment system.

Component Location:
The aftertreatment intake NOx sensor is mounted on the engine near the turbocharger turbine outlet.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected a mismatch between the engine’s electrical system voltage and the NOx sensor voltage rating.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber check engine lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

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 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. Calibration incompatibility between aftertreatment intake NOx sensor and ECM calibration.
2. System voltage is incorrect for the installed aftertreatment intake NOx sensor part number.
3. Incorrect aftertreatment intake NOx sensor is installed in exhaust system.
4. Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.
5. 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.