Detroit DD15 GHG14 (2014-16) Fault Code: SPN 3216 FMI 2 (ACM) Selective Catalyst Reduction Inlet NOx Sensor Rationality Error

DESCRIPTION:
This fault code sets when the difference between the expected NOX ppm and the actual NOx ppm is greater than 200 ppm.

MONITORED PARAMETER:
Aftertreatment inlet NOx sensor.

TYPICAL ENABLING CONDITIONS:
General Enabling Conditions: Engine is not in regeneration and operating at high speed and loads.

Engine Parameter:
1. Engine Speed (rpm):
– Min: 1350
– Max 1600

2. Torque (Nm):
– Min: 1100
– Max: 1500

3. Battery Voltage (Volts):
– Min: 11.08

4. Engine Coolant Outlet Temperature:
– Min: 70°C (158°F)

5. Ambient Temperature
– Min: -8°C (17.6°F)

6. Barometric Pressure (mbar):
– Min: 755

7. Time Since DPF Regeneration (min.):
– Min: 15

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
150 seconds (2 cycle)

DASH LAMPS:
MIL

ENGINE REACTION:
None

VERIFICATION:
1. Warm up the engine and ensure engine is not in regeneration mode.
2. Drive a fully loaded trailer on highway and maintain above enabling conditions for 150 seconds.

NOTE: If any other EGR codes are active, fix those first.

PROBABLE CAUSES:
1. Inspect the entire air inlet system, charge air cooler, and EGR piping/hoses.
2. Check for failed injector.
3. Check the aftertreatment system for leaks/damage.
4. Perform a high idle regeneration.