Detailed guide for SPN 3251 FMI 2
Back to top ↑Erratic DPF pressure usually means tubes or wiring, not “your DPF exploded.” Check tubes for soot blockage and tiny cracks that only leak under vibration.
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SPN 3251 FMI 2: DPF differential pressure signal erratic – false restriction readings
Quick Answer
DPF differential pressure signal erratic – false restriction readings
Code
SPN 3251 FMI 2
Severity
Warning
Applies to
Volvo
Can I drive?
Driving suitability is not established by this code alone.
Common Symptoms
- Random regen behavior
- DPF readings jump around
- Intermittent MIL
Likely Causes
- Plugged/cracked pressure tubes
- Loose connector/ground
- Sensor failing intermittently
Common Fixes
- Inspect/clean pressure tubes first
- Check connector pin tension and grounds
- Replace sensor if instability remains
Full technical sections↓
What does SPN 3251 FMI 2 mean?
Back to top ↑DPF differential pressure signal erratic – false restriction readings
Images for SPN 3251 FMI 2 (location, common failures)
Back to top ↑
DPF diagram (general). Differential pressure sensing is used to estimate restriction/soot load.
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Video walkthrough for SPN 3251 FMI 2
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Freightliner Cascadia DPF Pressure Fault (SPN 3251) Discussion
Channel: Truck Repair Explained • View in BigRigFaults Media • YouTube source
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Mechanic community notes for SPN 3251 FMI 2
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