After driving this car since Nov 2014 I have become accustomed to the glow plug light not coming on when starting the car or coming on for a flicker

During the recent cold weather at -4,-5 degrees it did come on briefly for a few seconds

However yesterday the outside temp on the car display said 12 degrees and today 6 degrees and the light came on for several seconds and this was for a 2nd trip both times??

Just puzzled why its comes on and stays on for longer in mildish weather but not cold weather??

Glow plugs are not really used for cold starting these days like they used to be on older diesels unless it is exceptionally cold, the kind of temps we don't see in the UK. They are there for emissions, smooth idling and various other functions these days including being used for DPF regeneration.

They are still a very important part of the engine system but you don't have to wait for the light to go out before starting the car, my Focus starts on the button no matter how cold it is and so did my ZTT which has the BMW M47 lump in it.

However if the glowplug light is flickering then I would think something is not quite right and some diagnostics might be able to shed some light on this.

I think on the MK1 the glow plug light is used as an additional engine management light... is this true on the mk2?

edit: having said that, from memory it flashes consistantly for fault, not flicker!

no - the light does not flicker.When I said 'coming on for a flicker' I meant it came on for a split second or so