I trust that Sarek and others know their stuff and that Landrover has a solid system here… but in my experience when you use these clutched to front driveline systems hard they like to overheat and shutdown. Granted my experience is with Porsche (Macan and Cayenne). At least in the Cayenne’s case for their performance models they had to add a special liquid cooling setup to deal with the heat from hard use. I have kept an eye out for anyone reporting issues with heavy sand and snow use which would be where I would expect heat problems and no one has reported any that I have seen.

 

The first error says that driver assist features are unavailable, then the warning message appears that says I’m in 2wd and I need to drive with caution. No idea why I’d be reduced to 2wd, that’s the major sticking point for me and why it’s a must that we get it fixed.

 

Nailed it on 4wd assuming hardware and software are operating properly. The problem almost certainly can be traced to a software update, and it seems like it’s taking some systems extra time to come online (15-30 minutes before I get a fully functioning vehicle again).

 

Still at the dealership. This is the update I received via text:We failed to communicate that the technician performed a hard reset on the DADC, “Driver Assistance Domain Controller.” We need to test drive the vehicle again to get through another drive cycle, if the lights reilluminate, then the technician will need to involve technical assistance through the engineers of JLR in the UK.

 

I've been down this path with our 2023. I had an infotainment issue where all the SXM preset favorite stations vanished. Dealer tech reaction was "we have never seen this before". No reset or software update would fix it. Dealer tech foreman got the engineers in the UK involved. They traced the problem to some module located under the driver seat. This module was VIN-specific and had to come from the Slovakia plant. It arrived in 2 weeks and once installed all was back to normal. I suspect you have a bad DADC that will need to be replaced.

 

I guess the discussion about which system performs better when it has failed is a good question. It would be interesting to take a new and old system and induce a fault in both systems. Like unplug a wheel speed sensor. Then drive both on a slippery hill to determine how wheels behave. My guess would be 1 wheel drive for both systems. The old will be 1 wheel drive on any of the 4 wheels and the new system would be 1 wheel drive on just only the rear wheels. The wheel with the least amount of traction will just spin and the vehicle stops moving. This is obviously when wheel slip occurs which would be very probable on the snowy driveway as in the OP. In my world, i believe the permanent rwd as a failsafe would be better because i will have our selectable air locker in the rear differential. So generally, a locked rear axle will get you out of most situations vs open diffs with 4wd. The biggest factor will be which system has more problems in general. My current my22 has had only one issue with a front wheel speed sensor. Otherwise absolutely no issues. Once i get my my25.5 130 in march, i will do some testing. If the new system has more of a likelihood to fault, i would prefer the older system simply because it would prove to be more reliable. Or maybe we orgganize a side by side test. I think it would be fun.

 

Latest text from dealer:

Hello, it appears the lights illuminating on your 2024 Defender 130's dashboard are related to the aftermarket lighting. The technician identified a 10 AMP fuse removed and replaced with two 10 amp fuses to power the lights. He removed the aftermarket wiring and installed a 10 amp fuse as intended by manufacturer, and the vehicle is operating as designed again. The technician started the vehicle 4 times at different occasions after the fact, and the lights have stopped illuminating.

Due to the presence of aftermarket work relating to your issue, this repair order is no longer warrantable through Jaguar Land Rover. The current bill is $880 for diagnosis, which breaks down to 4 hours of diagnosis.

End of text

I responded by telling them that the grill light was installed at least 60 days before we started having our issues. I’m also not quite sure how the problem resolves itself after driving for 15-30 minutes. If the fuse was the problem, wouldn’t it continue to be a problem for the entire duration of our drive? They responded by saying that LR’s are extremely sensitive and they’ve seen cars stop running because of an incorrect fuse.

I still think it was a software update, but can’t prove it. I’ve contacted the company that sold the grill light/fuse/instructions (very reputable company in the UK).

Any recommendations here?

 

Depends on what circuit the lights may have tapped into. Do you know? (actually the more specific you can be the more I can delve into wiring diagrams and see if I can hunt down any potential overlap... I love these sorts of mysteries and I'm off work today and it is raining... haha)

BTW -- Are these Triple-R lights (the super expensive ones?) My local JLR dealer is $240 an hour which would have been $960 so at least you have a cheaper labor diagnosis lol.

An aux light in the front grille throws the L663 into 2WD mode and renders all driver assist functions unusable? I still think that's insane.

 

You rock! Thank-you.

At about 15:30 in the linked video they show the fuse setup. I have also attached a pic.

 

Hmmm. Just watched the video of the installation provided by Hunter Prestige and the reason given by your dealer makes no sense as to the cause they claimed. First, a simple fuse tap was performed. Their explanation that “a 10 amp fuse was removed and replaced with two 10 amp fuses” is not exactly accurate, as they phrased it. The original fuse was still protecting the source, as it was all along. The fuse tap was merely ‘borrowing’ power from that supply to power the grill light. The grill light, being LED, most likely has such an insignificant power draw so as not to interfere with whatever component the original F7 fuse was protecting. These fuse taps are utilized all the time and should have no bearing on your related problem. Second, I’m sure this is not the first LED grill light that Hunter Prestige has sold, or has been installed in their market saturation. Otherwise this problem would have cropped up in each and every previous installation and we would have heard of this as a recurring problem with their product. Not knowing who did your aftermarket work, is it possible that they used a fuse other than the F7 fuse as specified by Hunter Prestige? If everything was done exactly as it was done in the video, then it would lead me to believe that the dealership executed some software fix/update and is using the ‘aftermarket’ work as being the root cause. And they love to pin the aftermarket work on the owner, thereby releasing them from doing it under warranty and placing the cost on you, the owner. Most warranties cite any aftermarket work as absolving them from responsibility for future problems. Even changing tire or wheel size from the original build gives them the excuse they need to blame engine or transmission problems as being caused by inordinate stress on the drivetrain by going outside of OEM specs. Just my hunch.