Active Regen Indication
The system is indicating the active regeneration process is occurring in the diesel particulate filter (DPF).
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What it means (plain English)
The computer has detected that the DPF is clogged and is currently cleaning itself by burning off soot at high temperatures. This usually happens when the engine runs under certain conditions for a specific duration, like in highway driving. It raises exhaust temperatures to about 600-700 degrees Fahrenheit.
What the computer is actually seeing
The engine control module (ECM) sees data indicating high soot loading in the DPF, leading to a command for regeneration initiated by the triggered parameters such as exhaust temperature and pressure readings.
What a healthy reading looks like
Soot loading level should stay below 45 grams. Exhaust temperature during regeneration typically exceeds 600 degrees Fahrenheit.
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. Check the DPF pressure differential sensor readings; compare inlet and outlet pressures. Should be less than 5 inches of H2O under normal conditions. If pressure is high, clean or replace DPF.
- 22. Inspect and test the DPF temperature sensors; ensure they are providing accurate readings. Compare values during active regeneration (should exceed 600°F). Replace if faulty.
- 33. Examine the exhaust system for restrictions; look for physical damage or foreign objects. Repair as needed.
- 44. Verify fuel quality and injector performance; ensure the correct fuel is being used and injectors are functioning properly.
Common causes
- High soot in the DPF
- Faulty temperature sensors
- Blocked or restricted exhaust system
- Insufficient fuel quality
- Malfunctioning EGR (Exhaust Gas Recirculation) system
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code active?
Yes, but it's recommended to complete the regeneration process to prevent DPF clogging.
Will this code come back after I clear it?
If the underlying issue causing the DPF to clog is not fixed, it will likely return.
Why do I see this code when paired with low fuel quality?
Low fuel quality can cause incomplete combustion, leading to higher soot production and more frequent regeneration.
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