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Exhaust-gas treatment – DPF/GPF, AdBlue
Exhaust-gas treatment – DPF/GPF, AdBlue
DPF and GPF/OPF filters trap particulate matter. AdBlue helps the SCR system reduce nitrogen-oxide emissions. Each system has a different function and requires a different response when a warning light comes on.
DPF and GPF/OPF – what does the warning light mean?
DPF is the particulate filter for diesel engines. GPF/OPF denotes the particulate filter for petrol engines.
In normal operation, trapped soot is progressively burned off during regeneration. Frequent short journeys can prevent completion. The filter warning light can therefore request a regeneration drive.
How can regeneration be supported while driving?
The engine must be warm. Always verify the exact procedure in your vehicle manual; speed, engine speed and driving time vary by engine.
Only carry out a regeneration drive when the relevant warning requests it and under the conditions in your vehicle’s owner’s manual. Do not copy speed, engine speed or driving time from a different model or engine. If the manual is unavailable or other fault symptoms appear, agree the next step with a workshop.
Observe speed limits and adapt to traffic and weather. An explicit instruction from the vehicle to stop takes priority.
Official manufacturer manualsOfficial manufacturer manualsOfficial manufacturer manualsOfficial manufacturer manualsOfficial manufacturer manualsOfficial manufacturer manuals Online manual availability depends on the model and production period; use the edition and supplements applicable to your vehicle.
The light stayed on or fault symptoms appeared
- If the light does not go out after driving as instructed, or repeatedly returns, book the vehicle for diagnosis.
- If the engine fault or EPC warning is on, the glow-plug light flashes, the engine runs unevenly, or the vehicle has a substantial loss of power, do not attempt another regeneration drive. Contact a workshop or roadside assistance.
- For a red warning, follow the vehicle instructions and stop safely.
- If the fuel-reserve warning is also on, refuel before any regeneration drive and then follow the vehicle manual.
DPF service life – J&S SERVIS experience
In our workshop experience, the DPF in some diesel vehicles is near the end of its service life at around 250,000 km. This is not a fixed replacement interval.
Soot burns during regeneration, but non-combustible ash remains in the filter. Actual filter condition, diagnosis and the manufacturer procedure determine whether professional cleaning or replacement is appropriate. This mileage must not automatically be applied to petrol GPF/OPF filters.
AdBlue – function, standard and composition
AdBlue is injected into the exhaust system of SCR-equipped diesel vehicles to help reduce nitrogen-oxide emissions. It has a separate tank.
| Item | Specification |
|---|---|
| Quality standard | ISO 22241-1, part of the ISO 22241 series |
| Solution designation | AUS 32, also DEF |
| High-purity synthetic urea | 32.5% by mass |
| Demineralised water | 67.5% by mass |
This is composition by mass, not a volume ratio in litres.
How to top up AdBlue correctly
- Park on level ground and switch off the engine and ignition.
- Use ready-to-use AdBlue meeting ISO 22241-1.
- Observe the minimum and maximum refill quantity shown on the display or in the manual.
- When using a suitable filling nozzle, stop after its first automatic shut-off.
- After filling, follow the recognition procedure in the manual. On some vehicles, first switch on the ignition only and wait approximately 30 seconds before starting the engine.
What happens if AdBlue is not topped up?
The vehicle warns of a low supply and displays the remaining range.
A running engine does not automatically switch off solely because AdBlue is exhausted. Once the displayed range reaches zero, however, the engine cannot be restarted after it is switched off. Do not postpone topping up until the final kilometres.
Topped up AdBlue but the message remains?
Recognition can take some time. On some vehicles, first switch on the ignition only and wait approximately 30 seconds before starting the engine. The procedure in the exact vehicle manual governs.