Detailed guide for SPN 2799 FMI 31
Back to top ↑If the pump cannot build pressure, dosing cannot happen.\n\nStart with leaks and crystals before replacing the pump.
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Share ↓SPN 2799 FMI 31Severity: Critical
SPN 2799 FMI 31: DEF pump prime/pressure build fault – pressure not achieved
Quick Answer
DEF pump prime/pressure build fault – pressure not achieved
Code
SPN 2799 FMI 31
Severity
Critical
Applies to
Check OEM application
Can I drive?
Driving suitability is not established by this code alone.
Common Symptoms
- DEF/SCR warnings
- Inducement risk
- DEF pressure not building
Likely Causes
- Pump weak or failing
- Restriction/crystals in line
- Air leak or fitting leak
Common Fixes
- Inspect for white crystals at fittings
- Verify pump power/ground under load
- Repair leaks/restrictions then retest
Full technical sections↓
What does SPN 2799 FMI 31 mean?
Back to top ↑DEF pump prime/pressure build fault – pressure not achieved
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