245700 and 245800 Fault Codes: DPF Heavily Loaded / Blocked (BMW N47, N57, B47)
245700 and 245800 are six-digit codes reporting an overloaded particulate filter on newer BMW diesels. They are the direct equivalent of 480A/481A on older M57 engines and follow the same two-stage logic.
— Tekin Code
245700 and 245800 are diesel particulate filter (DPF) codes written in BMW's six-digit format and stored by the DDE. 245700 means "particulate filter highly loaded, exhaust back pressure high", and 245800 means the filter is heavily contaminated. You will see them on newer diesels with N47, N57, B47 and B57 engines, and they are the exact counterpart of the 480A/481A pair on older M57 engines — the logic is identical, only the code format has changed.
What Do 245700 and 245800 Mean?
The DPF traps soot from the exhaust and cleans itself at intervals through a burn-off cycle called regeneration. The DDE tracks how full the filter is using the differential pressure sensor and a calculated soot model. When regeneration repeatedly fails to complete, soot builds up, back pressure rises and 245700 is stored. Keep driving at that point and the blockage moves to an advanced stage, adding 245800.
The difference between the two codes is not only severity but the options you still have. At the 245700 stage a correct drive cycle or a service regeneration is enough on most cars. At the 245800 stage the DDE usually refuses regeneration altogether, and removing the filter for cleaning or replacement comes into play. Because newer engines run their regeneration strategy more often, the gap between these two stages can be surprisingly short in short-trip use.
Code .............. 245700
Definition ........ Particle filter system: filter highly loaded
(exhaust back pressure high)
Code .............. 245800
Definition ........ Same system, later stage: filter heavily contaminated
Module ............ DDE (Diesel Engine Control Unit)
Format ............ 2457/2458 = fault location, 00 = fault type
Older equivalent .. 480A / 481A (same fault on M57 engines)
Severity .......... High - regeneration blocked, risk of DPF replacement
Common engines .... N47, N57, B47, B57 (F and G series diesels)
Symptoms
• DPF warning light and Check Engine light; some cars show an "Exhaust gas filter" message.
• Power limitation and limp mode; the car hesitates at higher RPM.
• Raised idle speed and the cooling fan running for long periods — a regeneration attempt.
• Higher fuel consumption and delayed throttle response.
• A sharp, hot exhaust smell when parked.
• Rising engine oil level — failed regeneration washes fuel into the oil.
• Symptoms deteriorating quickly with short city journeys.
Possible Causes
• Short journeys and low-speed use — the engine never reaches regeneration temperature. The most common cause.
• Regeneration interrupted again and again; the car is switched off before the cycle completes.
• An EGR fault or sooted EGR cooler raising soot production (see codes 290900 and 4501).
• A faulty differential pressure sensor or a soot-blocked pressure hose; the code appears even with a clean filter.
• Drifted exhaust gas temperature sensors — the DDE never starts regeneration at all.
• Leaking injectors or a poor spray pattern.
• Incomplete combustion caused by charge pressure problems (see 244C00).
• Unsuitable engine oil — not using low-ash oil accelerates ash buildup.
• Ash loading: at high mileage the filter fills with ash rather than soot, and regeneration no longer helps.
Diagnostic Steps with OBDThink
The goal is to settle two things: is the filter genuinely full, and which stage are you at? Those two answers decide whether the road ahead is cheap or expensive.
• 1. Scan all modules: is 245700 active, 245800, or both? With only 245700 stored, the regeneration window may still be open.
• 2. Read soot load and ash load separately. High soot with low ash means regeneration will work. High ash means the filter has reached the end of its life.
• 3. Check how many kilometres have passed since the last regeneration and how many attempts failed. Frequent starts that never finish point to the driving profile.
• 4. Compare differential pressure at idle and at 2500 RPM; at idle it should be close to zero.
• 5. Watch exhaust gas temperatures before and after the DPF live; if they have drifted, regeneration is never triggered.
• 6. Check the oil level and oil dilution value — a rising level means regeneration attempts are washing fuel into the oil.
• 7. Look for codes that increase soot production: EGR and charge pressure codes hold the lasting fix.
• 8. Inspect the pressure hoses; a soot blockage will mislead the sensor.
Reference values (vary by engine)
DPF status:
Soot load (calculated) ........ < 24 g normal, > 40 g critical
Ash load ...................... rises with mileage, cleaning does not reduce it
Differential pressure (idle) .. ~0 - 10 mbar
Differential pressure (2500 RPM) 20 - 60 mbar (far higher when blocked)
Regeneration:
Passive regeneration .......... 280 - 350 °C exhaust gas temperature
Active regeneration ........... 600 - 700 °C
Typical interval .............. every few hundred kilometres
EXAMPLE OF A FAULT:
245700 active, soot 36 g, ash low -> drive cycle or service regeneration
245800 active -> DDE refuses, filter removal on the table
Low soot but code present -> suspect the pressure sensor/hose
Log soot load with OBDThink on a long journey. When regeneration starts you see the value fall live; if it never falls, the cycle is not completing and the problem lies in the system rather than in your driving habits.
The Fix
• A correct drive cycle: once warm, drive for about 45 minutes at a steady speed with electrical consumers switched on. At the 245700 stage this is enough on most cars and costs nothing.
• Service (forced) regeneration: started with a diagnostic tool. Low cost; at the 245800 stage the DDE usually refuses.
• Differential pressure sensor and hoses: clear them if blocked, replace the sensor if drifted. Low cost and easily missed.
• Exhaust gas temperature sensors: replace a drifted sensor. Low to moderate cost.
• EGR and injector side: repair them if they are the source of the soot — this is where the lasting fix lies. Moderate to high cost.
• Off-car filter cleaning: a high success rate as long as ash content is not excessive. Moderate to high cost.
• DPF replacement: the only option once ash load is high. High cost.
• Engine oil change: if regeneration has diluted the oil, it must be renewed too. Low cost.
After the filter is cleaned or replaced, the soot and ash counters must be reset. Without a reset the DDE keeps assuming it is running with a full filter and the code returns immediately.
Can You Still Drive With These Codes?
The moment you see 245700 the clock starts: carrying on with short trips pushes the code to 245800 and destroys the cheap option. The bigger risk is a rising oil level — failed regeneration attempts wash fuel into the sump, and an overfilled sump can wreck the engine. If the dipstick reads above maximum, do not drive; have the car recovered.
If you see the same fault on an older M57-engined BMW, it appears as 480A/481A; the logic and the route to a fix are identical. In either case the correct order is: read soot load with OBDThink, establish the stage, find out why regeneration is not running and fix the root cause. Then clear the fault memory and confirm live, over a few long drives, that soot load really does fall.