I have the "Engine malfunction" message displayed on my 2009 Focus 1.6 diesel econetic.

Ive run through the "self diagnostic" by holding down the set/reset knob, and at the DTC codes, it says,

"DTC #Codes

NONE"

I also have a little diagnostic scanner of my own, and it shows nothing.

I did however, unplug my scanner when i wasn't supposed to, (the ignition was still on), and I've been told that this could've caused the "engine malfunction" message.

But the "engine malfunction" message came up a week or 2 after i used the scanner, is that possible?

Ive also been told that, by unplugging the battery, it may reset the "engine malfunction" message. Is that advisable? as i will try everything to avoid another trip to the mechanics, and £25 a time on the scanner, its money i don't really have at the moment.

Confused as to why it won't show up on my scanner though, any help is much appreciated.

The test mode on the instrument cluster doesn't show all fault codes, only those related to the cluster I believe.

Could be that the fault logged is an internal Ford code rather than a DTC which are generally those required to be read by the common protocol for OBD2, so you'd maybe need Ford IDS type software to read it. It's very unlikely the scanner caused the fault to come up 2 weeks later, my money's on it being totally un-related.

Disconnecting the battery may well clear the fault, it is worth trying and not a risky option at all. Just means you'll have to re-enter your radio code, maybe reset the 1-shot windows and some of the audio settings too.