I bought my e90 325d 2007 with unnervingly clean exhaust tips and shortly after having DPF warning light come on. I drove 1,000km later still on and even after thrashing for miles on the motorway. Checking engine temp was above 75c etc etc – no joy. I did an extensive research, and finally enabled the car to perform a regen, with the help of Inpa K+DCAN USB cable. In fact I think Any BMW code scanner will do. If interested this one I bought: http://www.obdii365.com/wholesale/bmw-inpa-k-can-with-ft232rq-chip.html
Car won’t perform re-gen if
- Engine temperature does not reach over >75c, and stay over this for a period of time (20/30 mins)
- Some Fault codes are stored – Mainly and Ironicly the DPF fault code itself.
- Over 20 Litres of Fuel in tank (I half filled the tank for good measure)
Preparation
Firstly I installed inpa software on my laptop. The software is in a mini dvd that came with the package. I read fault codes and cleared them. Within a few miles drive I plugged in and checked again, they where back. I guessed these codes where stopping the car regenning and it was stuck in a loop.
How to do the BMW PDF re-gen
– I engaged the engine temp in hidden OBC so i could see temp.
– Plugged in laptop to car (battery fully charged)
– Went for drive on M5.
– Engage Cruise Control – Adjust car to over 50mph so engine temp runs at over 75 – my temp was reading 76 to 79
– Every 10’seconds clear the fault codes or take a passenger and get them to keep hitting the clear button on your fault code scanner.
– Look at your OBC temp reading.
– After about 10 miles my temp started rising and peeked at 93c, this is DPF doing its thing.
– Rear view mirror = sooty clouds occupied by eggy smell later.
– Exhaust tips sooty.
I suspect the EGR thermostat was the initial culprit but once it throws the DPF warning fault codes keep the car stuck a loop. I noticed the car was storing the dpf code before it was reporting it on the dash when i was driving too. So the need to keep clearing codes obsessively when driving.
Hope this helps any E90 owners.
