DPF regeneration
QI have a 2013 BMW X1 2.0 sdrive 1.8d (engine code N47). I think that the DPF now needs replacing as I have replaced the MAF sensor that was preventing the vehicle from going into regen. If you could take a look at the screenshot that I have sent to you please, can you give me your opinion if it needs replacing or can you suggest some other things to check before I carry out replacement of the DPF.
Actions so far: rough running earlier this year, MAF sensor renew, regen status checked sometime after MAF replacement, 480A fault code and ~2500km since regen.
Request regen with diagnostic. Drive, not regen. Request regen. Drive, no regen. Cleared fault, request regen. Drive, no regen.
DFP fuel additive. Checked regen status a couple of weeks later, ~600km since regen. 480A present. Cleared fault, request regen. Drive, no regen. 481A and dash warning light on. Request regen and drive a couple of times, no regen. JLM Foam DPF Cleaner used. Drive, no regen but no dash light.
Checked ~2000km since regen. Dash light and 481A error. Code cleared, drive, “Regen Active” showed on diagnostic but soot level not reduced and light back on. Long drive, cleared code, 481A back on. Leon Pratt
AThe codes 480A and 481A as showing on the diagnostic scan photo you sent, do indicate that the diesel particulate filter is blocked and that an excess back pressure is present, but the DPF should not be replaced until the full reason for the codes showing is known.
The DPF should normally regenerate, and as this is not the case, then there may be contributing factors that should be investigated before the replacement.
You have already renewed the MAF sensor and so this can be eliminated, but the induction system should be checked for any leaks. The integrity of the engine temperature sensors should also be checked to ensure the reading are accurate – the regeneration of the DPF is dependent on the temperature. The gas temperatures showing on the screenshot you have sent before the DPF of 64.36°C is below the 75°C required to begin the regeneration. The upstream exhaust-gas temperatures will be between 280 and 350°C during the regeneration.
The pressure sensors should also be checked to ensure that these are reading and operating correctly.
There is also a common problem that can occur on your X1 with a failure of the EGR system, and again this may prevent the regeneration from being performed. A blocked DPF is usually the result of a problem not the source, and so by replacing the DPF you may be able to remove the codes, but the underlying problem may remain. At just over 70,000 miles the DPF should not need replacing, and I would be reluctant at this stage to carry this out without first identifying the source of the problem.
It may be worth trying a forced stationary regeneration which should be possible with suitable diagnostic equipment.