Quick update on Diagnosing my 2012 Mk7 Transit DPF failing to regenerate and the soot content building. Thought I would write this to help any future people with the same problem. I had the usual cog and exclamation light come on and go off a few times and then the EML light came on and stayed on. At the time I didn’t have the diagnostics kit so used my RAC start from home, he ran a static regen which failed after 30 minutes or so, the soot content had not reduced. They didn’t offer much other help. The fault codes registered were P0672; Cylinder 2 Glow Plug Circuit, P244C; Catalyst temperature too low during regeneration, bank 1 and P2463; Diesel Particulate filter – soot accumulated.
So I started my own diagnostic without any ECU interface at the time. (Pre checked all fuses, none had blown):
1. Check wiring at the exhaust loom multi-plugs for breaks. There were no obvious breaks which was a good sign.
2. I used a Multimeter to test, while the engine was running, that I was receiving 5V at each of the temp sensors multi-plugs. That checked out ok, so I removed the temp sensors, hooked the Multimeter up at the highest resistance setting and applied a heat gun to the sensors and watched the resistance reduce as its supposed too. There is a good YouTube video for this too if you search for it. This confirmed the Temp sensors were working correctly.
3. As I couldn’t initiate a static regen I couldn’t test the power to the Vaporiser glow plug but I checked its resistance by placing the Multimeter across the wiring connections on the Glow plug end of the multi-plug, 1 Ohm was a good value.
4. This left 4 possible failures, that I could think of, one there was no fuel being supplied to the Vaporiser, removing the fuel feed line off the pump it was full of fuel so I was happy with that.
5. Second the pressure differential sensor used to measure how blocked the DPF is by detecting the delta value across the DPF was failing or the pipes were blocked. I popped both of these off from the DPF and they looked in good nick. I suppose you could pop them off from the sensor and blow down them to check for a blockage but I didn’t as It seemed unlikely. Also this has never been mentioned as far as I am aware as a failure on the Transits so I dismissed it as very unlikely. Especially as I was getting a blocked reading to the ECU that the DPF needs regening.
6. Thirdly the DPF had somehow failed internally, there were a few cases I read online where they needed a replacement and everything else was working fine but my Van only has 50K so this seemed unlikely too.
7. Finally then I suspected the Vaporiser was blocked, this appeared to be a common fault stopping or reducing the amount of fuel being delivered into the exhaust gasses to raise the temperature to burn off the soot. I initially suspected this after the temp sensors checked out ok and the static regen did not reduce the soot load. I concluded the DPF was not getting up to temperature. (I should have checked the live data when the RAC guy did the static regen, I think they are supposed to hit around 600°C).
So to remove the Vaporiser, this was a tricky bugger and seemed near impossible to do while the exhaust was still in place. So I removed the two heat shields around the exhaust to give a little more access. I then removed all the wiring and disconnected the vaporiser fuel line. Undo the 3 nuts securing the flexible exhaust to the turbo and then remove the remaining exhaust restraints. I didn’t bother to split the back box off the DPF as its always a ballache trying to hammer them out and back in again so I just removed the entire exhaust train. Removing the exhaust took me approximately 2 hours to do. I could then crack the Vaporiser nut by inserting a rod into the flexible exhaust to restrain it and undoing the 22mm nut. One Vaporiser unit removed!
Now I didn’t have a vacuum kit to test for a blockage of the Vaporiser so I just did the blow test. Blowing down the metal fuel line (I’d remove the rubber tube) while holding the vaporiser nozzle underwater to check for bubbles. None came out so I was satisfied I had a blocked Vaporiser before spending over a hundred pounds on a replacement. I ordered one from ford (haggled to get trade price) and refitted it applying some copper brake grease to all the nuts/threads and reconnected the exhaust system.
Now to perform the static regen without the ECU interface, I chose to go for the Forscan diagnostic free download and ECU interface from
http://www.ebay.co.uk/itm/ELM327-USB-mo ... SwZVlXrBVO. This seemed to be cheaper than buying a VMC clone and risk getting dodgy software sent though. Unfortunately it didn’t arrive in time so I phoned my RAC and got them to investigate my EML light, he performed a static regen, I crossed my fingers and Wahay the soot load starts reducing down to an acceptable level…..Regen complete. At the end of the regen it had got through 60% and the soot load was at 0%. It then auto finished and the EML light went out. I assumed he reset the DPF values before he started the static regen, I can’t remember. So I am back on the road again with a happy van. No money wasted at the garage, a little time spent learning about diesel exhaust systems and plenty accomplished.
I hope this helps anyone else out with a similar problem.