Detailed guide for SPN 3515 FMI 2
Back to top ↑Bad EGR flow feedback pushes the engine into wrong EGR strategy.\n\nThat can create soot problems that show up downstream as aftertreatment faults.
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Share ↓SPN 3515 FMI 2Severity: Warning
SPN 3515 FMI 2: EGR differential pressure signal erratic – unstable flow feedback
Quick Answer
EGR differential pressure signal erratic – unstable flow feedback
Code
SPN 3515 FMI 2
Severity
Warning
Applies to
Check OEM application
Can I drive?
Driving suitability is not established by this code alone.
Common Symptoms
- EGR performance faults
- Surging idle
- Increased soot / frequent regens
Likely Causes
- DP sensor lines plugged/cracked
- Loose connector
- Sensor failing intermittently
Common Fixes
- Inspect/clean pressure lines
- Check connector and grounds
- Replace sensor if instability remains
Full technical sections↓
What does SPN 3515 FMI 2 mean?
Back to top ↑EGR differential pressure signal erratic – unstable flow feedback
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