Diesel particle filter in DDE 7

For heavy vehicles, to comply with the EU4 legislation taking effect as of 2005, a coated diesel particle filter is necessary.
This diesel particle filter separates the soot particles in the exhaust gas with high efficiency (> 95 %). The diesel particle filter has no influence on the nitrogen oxide (NOx) emissions; these are reduced by measures inside the engine.
The particle 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.

The diesel particle filter on N47 engine is at all times fitted close to the engine. (exception: 520 D, right-hand drive vehicles: installation in the underbody)

In an identical way to the previous generations of the BMW diesel engines, with DDE 7 the oxidation catalytic converter and diesel particle 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 gas temperature sensor before the particle filter and catalytic converter for initiating the filter regeneration. (See graphics, component 2. The ”exhaust gas temperature sensor before the particle 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).
  
• Lambda oxygen sensor before the oxidation catalytic converter to sense the excess-air factor (see graphics, component 1).
  
• Extended software of the engine management system.
  

New CBS strategy:

With introduction of the new CBS strategy for BMW diesel models (first deployment: in the E70 as of 09/2006 in DDE 6), the remaining distance for the particle filter can be read out via the control unit functions. As the particle filter is no longer a CBS function, two new faults indicate limited remaining availability:

• Fault 452A appears when the particle filter has exceeded most of the maximum running distance 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 particle filter has been exceeded.
  
  

Differences to DDE 6.x:

The diesel particle filter is used in the engine management 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 test for the DDE 7 implementation mean a test of the electrical swirl-flap actuator. This actuator is different in the DDE 6 and DDE 7 implementation.
  
  

Uses:

The diesel particle filter is used in the engine management system generation DDE 7 as follows and initially in the following versions:

• E8x with N47uL and oL left-hand drive and right-hand drive vehicle as of 03/07: engine-proximate particle filter
  
• E9x with N47uL and oL left-hand drive and right-hand drive vehicle as of 03/07: engine-proximate particle filter
  
• E6x, E8x and E9x with N47oL left-hand drive as of 09/07: engine-proximate particle filter
  
• E60 right-hand drive vehicles as of 09/07: installation of the particle filter in the underbody
  
• E8x and E9x with N47oL right-hand drive vehicle as well as E8x with N47TOP(TL) as of 09/07: engine-proximate particle filter
  
• Other E6x with N47: engine-proximate catalytic converter
  
• E83 with N47 left-hand drive and right-hand drive vehicle as of 09/07: engine-proximate particle filter