SPN 411 FMI 2 — EGR diff pressure — erratic
Applies to: Detroit · Navistar · Paccar · Volvo · Common on DD15
EGR diff pressure — erratic.
Your SPN/FMI rides along, so nearby mechanics see the fault before they quote you.
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.
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.