Diesel particulate filter in DDE 7.x
For heavy vehicles, a coated diesel particulate filter is needed to meet the requirements of the EU4 legislation valid from 2005. The diesel particulate filter separates out the soot particles in the exhaust gas with a high level of efficiency (> 95 %). The diesel particulate filter has no influence on the nitrogen oxide (NOx) emissions; these are reduced by measures inside the engine. The particulate filter system used at BMW requires no maintenance and is designed to last the service life of the vehicle. A fuel additive for filter regeneration is not necessary for BMW vehicles.
On N47 engines, the diesel particulate filter is always fitted close to the engine. (Exception: 520 D, RHD vehicles: installation in the vehicle underbody)
In an identical way to the previous generations of the BMW diesel engines, with DDE 7 the oxidation catalytic converter and diesel particulate filter are fitted in the same housing (see graphics, components 4 and 5). [comparable with the housing solution in the R56 MINI diesel (designation: W16)].
The filter element consists of a ceramic monolith made of silicon carbide that is resistant to high temperatures. The filter element is 50% porous and has been given a platinum-based, catalytic coating. This coating ensures that the soot ignition temperature is reduced or the reactivity is improved, thus ensuring good regeneration characteristics of the particulate filter.
Components of the new particle filter system:
The components of this system are similar to the implementation in BMW M47TÜ2 (DDE 6.x) diesel engines:
- Exhaust system with catalytic coated soot particle filter
- Throttle valve for exhaust gas temperature increase within the engine
- An exhaust temperature sensor upstream of the particulate filter and catalytic converter for initiating filter regeneration. (See graphics, component 2. The ”exhaust temperature sensor upstream of the particulate filter” that was present in previous diesel generations is no longer required).
- An exhaust backpressure sensor to estimate the filter load while the vehicle is being driven (see graphics, component 3).
- Oxygen sensor upstream of the oxidation catalytic converter to sense the air ratio (see graphics, component 1).
- Extended software of the engine control.
New CBS strategy in the DDE 6.x:With introduction of the new CBS strategy for BMW diesel vehicles (first deployment: in the E70 as of 09/2006 in DDE 6), the remaining distance for the particulate filter can be read out via the control unit functions. As the particulate filter is no longer a CBS function, two new faults indicate limited remaining availability:
- Fault 452A appears when the particulate filter has exceeded most of the maximum mileage and serves as information/request for competent filter replacement in the BMW workshop.
Fault 4D4A appears if no measures are taken despite the request for filter replacement being issued and the total running distance of the particulate filter has been exceeded.
Differences between the new DDE 7.x and DDE 6.x:The diesel particulate filter is used in the engine control system generation DDE 7 as follows and initially in the following versions:
- The DDE 6 fault 4166 ”insufficient flow resistance” is no longer present. The functionality of this diagnosis is still present. The corresponding fault is covered by fault code 45CE.
All test module references to the swirl-flap actuator check mean implementation of a check of the electrical swirl-flap actuator for the DDE 7. This actuator is different in the DDE 6.x and DDE 7.x implementation.
Deployments of the particulate filter with DDE 7.x:
The diesel particulate filter is used in the engine control system generation DDE 7.x as follows and initially in the following versions:
- E8x with N47uL and oL left hand drive vehicle and RHD as of 03/07: engine-proximate particulate filter
- E9x with N47uL and oL left hand drive vehicles and RHD as of 03/07: engine-proximate particulate filter
- E6x, E8x and E9x with N47oL left hand drive vehicles as of 09/07: engine-proximate particulate filter
- E60 RHD as of 09/07: installation of the particulate filter in the vehicle underbody
- E8x and E9x with N47oL RHD as well as E8x with N47TOP (partial load) as of 09/07: engine-proximate particulate filter
- Other E6x with N47: engine-proximate catalytic converter
- E83 with N47 left hand drive vehicles and RHD as of 09/07: engine-proximate particulate filter
- All other BMW vehicles after 09/07: engine-proximate particulate filter
- BMW US diesel M57TÜ2TOP US with DDE 7.3 as of 2008: engine-proximate particulate filter