SPN 411 FMI 2 — EGR diff pressure — erratic
What it means: EGR diff pressure — erratic.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Clean/inspect EGR pressure lines
Don't risk it — look up listed providers near you and give them this SPN/FMI when you call.
Listed providers nearest Baltimore, MD
Closest first. Tell them SPN 411 FMI 2 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Baltimore, MD · (443) 680-6789
- 0.0 mi away — based in Baltimore, MD · (410) 544-3888
- 24 hour Mobile Diesel Truck Engine Repair DEF Repairs On Site Services Road Service Laptop Diagnostic Tractors & Dump Truck☎ Call0.0 mi away — based in Baltimore, MD · (443) 591-3631
Applies to: Detroit · Navistar · Paccar · Volvo · Common on DD15
What SPN 411 FMI 2 means
EGR diff pressure — erratic.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Plugged EGR cooler
- EGR valve sticking
- Sensor hose plugged
- Plugged lines
- Sensor
- Plugged hoses
- Pressure line plug
First moves (roadside)
- Clean/inspect EGR pressure lines
- EGR cooler flow test
- Inspect lines
- Inspect hoses
FAQ
EGR diff pressure — erratic.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Plugged EGR cooler. Other possibilities include EGR valve sticking; Sensor hose plugged; Plugged lines; Sensor; Plugged hoses; Pressure line plug.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside SPN 411 FMI 2, or share the same subsystem.
- EGR diff pressure high (SPN 411 FMI 0)
- EGR Differential Pressure — Voltage High (SPN 411 FMI 3)
- SCR Operator Inducement — Severe Derate Active (SPN 5246 FMI 0)
- Aftertreatment 1 Diesel Particulate Filter Differential Pressure - Data Valid But Above Normal Operating Range, Most Severe Level (DPF severely restricted / plugged) (SPN 3251 FMI 0)
- Aftertreatment 1 Diesel Exhaust Fluid Quality - Data Valid But Below Normal Operating Range, Most Severe Level (DEF quality/concentration incorrect) (SPN 4364 FMI 1)
- DPF Differential Pressure — Data Erratic (SPN 3251 FMI 2)
- DEF Dosing Unit — Not Responding Properly (SPN 3361 FMI 7)
- SCR Conversion Efficiency — Below Threshold (SPN 4364 FMI 18)
Find a mechanic or related guides
General diagnostic guidance for heavy-duty diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack). Not a substitute for a scan-tool diagnosis on your specific truck.