I've read some similar forum posts about this issue but yet to discover an answer! I have a 2012 MK3 Focus 1.6L Econectic Diesel. The Auto Stop/Start system functioned perfectly for the first 3 years but since then it rarely (but very occasionally) turns off. So far I have check the battery voltage (it's ok) and topped the battery up with a Nejčastější závady palubních desek modelu Ford Focus II jsou: Vadné řídící procesory. Odcházející I2C kontroléry. Závady v oblasti napájení a stabilizace napájecího napětí. Vadné speed motorky. Špatně se zobrazující znaky na LCD displeji či celkově nefunkční LCD displej. Závada se většinou objeví z čista jasna. What can sometimes happen is although the 2 systems seem different, you don't know about where the wiring runs close or if they have close terminals in the Powerbox. Take it to one of the 3 places I mentioned and ask for them to clear your computer. Don't know the cost of the particulate filter, but it may need replacing if the Code comes up JWbfl.