Detroit DD15 GHG14 (2014-16) Fault Code: SPN 2631 FMI 1 (MCM) Low Air Flow

DESCRIPTION:
This fault code sets when the engine is in smoke mode control for an excessive amount of time due to inadequate clean airflow into the engine.

MONITORED PARAMETER:
Smoke mode operation.

TYPICAL ENABLING CONDITIONS:
General enabling conditions: engine is in smoke mode.
Specific Enabling Conditions: See table below.
1. Engine Coolant Outlet Temperature:
– Min: 65°C (149°F)
2. Barometric Pressure (mbar):
– Min: 755
3. Ambient Temperature:
– Min: -8°C (18°F)

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
13 seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Derate 25%

VERIFICATION:
Once engine is at standard operating temperature, operate engine on highway, coast for 30 seconds and then snap throttle and keep throttle at 100% for a minimum of 15 seconds.

PROBABLE CAUSES:
1. If any other faults are active fix those first.
2. Check air intake system for leaks/failures.
3. Wastegate actuator failure.
4. Plumbing to and from the actuator.
5. Airline to wastegate solenoid for the turbo.
6. Intake manifold pressure/temperature sensor.
7. Intake manifold pressure/temperature sensor harness/wiring.
8. EGR delta p sensor.
9. EGR delivery pipe delta p pressure ports.
10. Remove the EGR cooler hot pipe, EGR crossover pipe, and delivery pipe. Check for excessive build up or blockage.
11. DOC inlet and DPF outlet pressure sensors and connector/harness.
12. DOC and DPF pressure tubes blocked or leaking.
13. Remove turbo inlet elbow and outlet pipe, inspect for oil or contamination.
14. Perform a parked regen.