Glow plug light

Hi Guys

Ever since Ive had my 2003 td4 my glow plug warning light has come on for a few seconds when ignition switched on and then extinguishes. Now the LED warning light and glow plugs does not come on at all even in cold weather. Had a look at relay and found that I'm getting battery voltage and ignition voltage. I believe the circuit to earth to operate the contacts of the relay to the plugs is controlled by the ECM. This does not seem to be happening. I put a wire to earth from the relay which then made a click and I found to be operating ok but does not put warning light on. Checked earthing wire brown/red from relay to ECM and it has continuity.Checked the resistance of the ECT sensor from wires from ECM which gave 4.25 at approx 12c which seems ok. The temp guage in dash seems to be working ok. The car takes a little longer to start on these cold mornings but once started seems a bit lumpy with a little smoke. After engine warm it fires up straight away without smoke. This is not so much of a problem now but I would just like to know if anyone has any ideas why this is not working. Been searching and reading for over an hour and found nothing like this.
Any thoughts appreciated.

Hi guys

No answers or surgestions yet. Any ideas please.

normally the glow plug will light for a few seconds if the temperature is low and then start the engine for some reason which I can not think off your is not that's why you are getting smoke and a bit ruff running first thing , have you checked the fuse?

Thanks teddywood1

Fuse 1 in the engine compartment is ok as I get an ignition feed to the relay. The ECM should earth it out so as to let the contacts in relay work. Seems that this is not earthing by the ECM.The glow plug light is operated straight from the ECM. Can't understand why this has happened all of a sudden.

If anyone has experienced this fault did they have it fixed at workshop.What was the outcome. What did they change fix ?