SOOT LEVEL EXCEEDED THRESHOLD
Indicates that the soot level in the diesel particulate filter (DPF) is too high.
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What it means (plain English)
The system measures the amount of soot trapped in the DPF. If it hits a certain level, it sets this code to warn you that the filter needs cleaning or replacing.
What the computer is actually seeing
The engine control module (ECM) calculates soot accumulation based on sensor readings from the DPF pressure differential sensor. It monitors pressures before and after the filter. When soot levels exceed the calibrated threshold, this code triggers.
What a healthy reading looks like
Normal DPF soot level is typically below 20 grams. If readings above 30 grams are detected, this code may set.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Inspect the wiring and connectors of the DPF pressure sensors for damage or corrosion.
- 22. Check the DPF for visible blockages or soot buildup. Ensure the filter is not excessively clogged.
- 33. Review the vehicle's driving history: Is it often used for short trips? If so, consider performing a forced regeneration.
- 44. Measure the soot level using a scan tool to see current readings. If above expected range, go to step 5. If not, clear the code and monitor.
- 55. Check the configuration of the DPF pressure sensors to ensure proper function. Replace if faulty.
Common causes
- Clogged or over-saturated DPF
- Faulty pressure sensors
- Infrequent regeneration cycles
- Excessive short trips causing incomplete combustion
- Fuel quality issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may be drivable, but continued driving with a clogged DPF can lead to reduced performance and potential engine damage.
Will this code come back after clearing it?
If the underlying issue isn't fixed, yes, the code will likely return after a short period of driving.
Why does it pair with SPN 2990?
SPN 2990 often indicates a low soot level warning, so both codes relate to the DPF's ability to manage soot effectively.
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