2021 Land Rover Defender P400 SE - interior lights will not manually switch on / off. They do turn on / off when the door is open / closed. Pressing and holding the center light to toggle between modes does nothing. The dealer had the headliner down to do the TSB to address the keyless entry issue discussed here. I am guessing this caused it, but that was several months ago, and the vehicle is out of warranty now. The dealer is pushing for $1K diagnostic fee saying it's not clear it was their fault.

1. Any ideas on diagnostics to try myself?
2. What is the best way to escalate to the dealer and LR if there's a disagreement?

I can't imagine what else caused this issue besides their mucking about in that exact area.

 

Buy the gap tool. Trust us. You’ll fix it yourself.

 

There is a software setting that could disable the manual clicking light switch? Both the tap on the dome light and the map lights don't work... thanks

 

DUDE! Same thing on mine 2 months ago when I got mine back from the exact same TSB. It's not software, it's not user error. Take it right back.

They screwed up a circuit - there is a separate circuit to turn on the same lights with the doors and to turn them on with on demand. (a bit confusing - but there's 2 ways to power the same light bulbs basically). So, yes, the lights still do go on when you open and close the doors, which is confusing, but they are wired that way. The circuit you have lost is called ON_DEMAND_INTERIOR_LIGHTING on the circuit diagrams of the car, by the way.

Guessing your sun visor lights also do not work (will you please check)?

On mine - they had pinched a wire on the drivers side sun visor -- screwed right through the wire, and shorted out that ON DEMAND circuit. I would bet 100 bucks that this is exactly what happened with yours. What is interesting is -- it did not blow the fuse. The circuit just stopped working. You would think it would blow the fuse. I checked it - it did not blow the fuse.

 

Wow, amazing that someone else is hitting this @nashvegas . Ours is currently at the dealer, so we can't check the visor lights but we're pretty sure they work just fine. After getting on the phone with the service advisor, we clarified that
1) The lights now work as expected after a BCM update
2) They were bull****ting us about wanting to find the root cause and add on another ~$800 diagnostic fee as maybe the software update wouldn't fix it permanently

More to come after we get a full resolution hopefully tomorrow.

ETA: no fuses blown for us either.

 

The sun visor lights are on the same circuit btw -- ON_DEMAND_INTERIOR_LIGHTING. Sounds like they've fixed it anyways, so that's good.

 

Update: The sun visor lights work and now everything works. There was a code saying there's a short on Circuit B on the BCM interior lighting which was corrected by "BCM enable output". Not sure if that's a software update or changing a setting. I suppose that may come back if it's actually shorted... Time will tell.

 

Hi! I’m having the exact same problem on my 2022 Defender 90. The interior lights still come on with the doors, but the on-demand interior lighting is completely dead.



On top of that, my ambient lighting also doesn’t work at all — no matter what I change in the menu or which level I select, nothing happens. Do you remember if the ambient lighting was working on yours when this issue occurred?



Do you think the ambient lighting could be on the same circuit, or is it a completely separate one? Any idea what the relationship might be?



Also, by any chance, do you still have the circuit diagram for the ON_DEMAND_INTERIOR_LIGHTING circuit?



Thanks a lot — this info is super helpful.

 

Ambient lighting - yes it worked. It’s a different circuit than the on-demand for sure, as far as I remember. On demand is just separate on/off signals to other lights that are part of the interior lighting circuit (ie another way to turn them on).

I just looked on my hard drive, I had printed this dang wiring diagram out and physically highlighted it with a yellow and purple highlighter when I took it into the dealer.

But here is the INTERIOR LIGHTING CONFIGURABLE AMBIENCE LIGHTING diagram (3 pages) . And a few others .