Cummins X15 CM2350 X116B Performance Series (2018 & Newer) Fault Code: 6461 PID: SPN: 3216 FMI: 2/2 Aftertreatment 1 Intake NOx – Data Erratic, Intermittent, or Incorrect

Lamp:
None

Reason:
An incorrect NOx sensor reading 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 when the aftertreatment diesel oxidation catalyst intake temperature is above 150°C [302°F], and the engine is in a motoring condition.

Conditions for Setting the Fault Code:
The Engine Control Module (ECM) detected the aftertreatment outlet NOx sensor reading was not changing with engine conditions or is stuck.

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:
1. To validate the repair, start and operate the engine to raise exhaust temperatures. This can be done by either driving the vehicle or initiating a stationary regeneration using the recommended diagnostic tool or equivalent.
2. The aftertreatment diesel oxidation catalyst intake temperature must be above 150°C [302°F] for 5 minutes before the aftertreatment intake NOx sensor can run its internal diagnostics.
3. Vary engine speed by 100 RPM for until the fault clears (may take up to 10 min).
4. The fault code status displayed by the recommended diagnostics tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
5. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs and passes.
6. 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.
7. 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. Malfunctioning aftertreatment intake NOx sensor.
2. Improperly installed aftertreatment intake NOx sensor.