Detroit DD13 EPA07 (2007-09) Fault Code: SPN 2631 FMI 1 (MCM, ACM) Low Air Flow
DESCRIPTION:Insufficient air flow.
MONITORED PARAMETER:Smoke mode operation.
TYPICAL ENABLING CONDITIONS:General enabling conditions: engine is in smoke mode.1. Engine Coolant Outlet Temperature:– Min: 65°C (149°F)2. Barometric Pressure (mbar):– Min: 7553. Ambient Temperature:– Min: -8°C (18°F)
MONITOR SEQUENCE:None
EXECUTION FREQUENCY:Continuous when enabling conditions met.
TYPICAL DURATION:13 seconds
DASH LAMPS:1. MIL2. 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.