I have the same issues, also a D300. did you find the solution for this problem? I think it's battery related. when the battey is not fully charged the message appears?

 

Not enough time passed to know. After I put it on the 5 amp charger it took only 3 hours to 80% full and was fully charged over night. I don't believe it was super low - would have taken a lot longer to get to 80%.

The Defender has been sitting since then. Will see if the message pops back up again.

 

My vehicle D300 experienced the same issue. When I went to the dealership, it was diagnosed as an alternator failure, and it took a few weeks to order the replacement parts and an additional 2 weeks for repairs. Then the issue has been fixed.
They said that this issue seems to be rare case even on the world wide.

By the way, if you continue to drive with the error, be careful because the battery will run out.
Try cycling the ignition on and off until the error disappears before long drive.

 

Thanks for this.

Do you know how it was diagnosed? Nothing is showing up when the scanner is plugged in, though it's never been scanned while the message is on the display. I can't get it to appear when the dealership has the car.

 

I don't know.

In my case, I often experience the error with a high probability if I wait for about two days after driving, so I informed the dealership and left it with them.

 

Sounds exactly like the issue I've got. Can't seem to interest the dealership that it's the alternator despite that being the first thing I guessed. When it happened the first time I opened the hood to make sure the belt was intact. The dealership seems to just want to scan for trouble codes, if there is no code there is no problem.

 

So an update, after fully charging the battery 2 weeks ago we have driven it a few times with gaps of 2 to 3 days in between. So far the issue hasn't popped up again.

I'm not convinced the issue is gone though.

 

Haha - I was right.

Message was back today. This time I let it run while waiting for roadside assist. By the time they got here an hour later, many other messages started coming on the dash. The tech tested the battery while the car was running and found it was not charging at all. The battery was at 8 volts. Soon after the car shut off and wouldn't restart on its own. After jump starting, the tech tested again and this time the battery tested at 14.5 volts while running. So it's an issue with the charging system. It doesn't charge well enough to keep the battery fully charged. Then once below some threshold of charge, it doesn't charge at all until you cycle the ignition.

Now I have to sort getting it back to the dealership.

 

Well, at least now you know what's wrong with it, which is half the problem with these intermittent faults.

l had a brand new Alfa Romeo that sometimes just stopped and wouldn't re-start for around 45 minutes. So by the time breakdown arrived it started fine and showed no faults.

Fortunately it eventually did it on the dealers forecourt. The fault turned out to be the fuel pump.

 

While true I'm not sure the dealership will be responsive to the information.

The first thing I checked the first time the message popped up was the alternator belt. Despite discussing the alternator as a probable issue with the service desk the first time around, the techs didn't check the charging system because there were no DTCs when they scanned it. They seem very "by the book". If that continues I'm going to be without the car for a long time while they screw around waiting for the computer to tell them what to do.