Auto Lights always on

[Vincintosh]

Good morning everyone. I've a 2004 406 coupé D9 2.2 Hdi. Yesterday in the early afternoon I was driving back home, when I passed under a tunnel and the auto lights turned on. But when I left the tunnel, they stayed on and never went off. Disabling the auto lights and turning the manual switch on and off will turn the lights off, but if I enable the auto lights again, they will come back on and stay on even if the sun is shining bright. This has happened in the past a few times (expecially if the car was dirty), but turning the auto lights off and back on always solved the issue. This time not. Does someone please have any ideas out there?

[GingerMagic]

The auto lights sensor is in the top middle of the windscreen, along with the auto wipers sensor - if your car is dirty then I guess the sensor thinks it's dark...??
It may also be a problem with the comms unit, not uncommon, but your symptoms are slightly different.
The auto lights can be disabled with PP2000, but I don't think the sensitivity can be adjusted.

[steve_earwig]

Yes it can, IIRC it's got 5 levels but I wouldn't have thought that could have changed, more like the sensor's gone blind

[Vincintosh]

Yes it can, IIRC it's got 5 levels but I wouldn't have thought that could have changed, more like the sensor's gone blind

How can I check if the sensor is broken? I'Ve already cleaned the windshield by the way

[steve_earwig]

That's a little beyond my experience I'm afraid, I think Peugeot Planet could help but I'm not sure if it can actually look at the levels coming out of the sensor or just operate the lights intendant of the sensor. Anyone? What about a BSI reset? Clutching at straws I know.

[Doggy]

I don't think there are any values you can monitor.
As Steve says there are several sensitivity settings, but I've never tried changing them.
GM is right about potential Comm2000 / stalk issue - my old 406 kept turning the auto lights back on by itself due to a dodgy stalk until I disabled the function in the BSI.

[Vincintosh]

I don't think there are any values you can monitor.
As Steve says there are several sensitivity settings, but I've never tried changing them.
GM is right about potential Comm2000 / stalk issue - my old 406 kept turning the auto lights back on by itself due to a dodgy stalk until I disabled the function in the BSI.

But i don't need to disable the auto lights function in the BSI, I have a dedicated button on the stalk. If i disable the auto lights, they stay off and never turn on randomly unless I turn them on manually as usual. Can the Comm 2000 still be the issue? I don't have a PP2000 though...

[GingerMagic]

Thing is, the dedicated button on the stalk could be the issue - it was on my old 406.
By disabling the auto lights with PP2000 then they are effectively made non functioning so the auto lights are permanently off, even if you turn them on with the stalk.
The button on the end of the stalk has a copper ring underneath which can deteriorate, I believe it's fairly easy to replace - I can try to find some pictures if you like?

As a thought, I think if you put your ignition on position 1 ( radio works but no dash lights ) and press the button for a few seconds you also switch off the lights permanently - I'm not 109% on this though....

[Vincintosh]

Thing is, the dedicated button on the stalk could be the issue - it was on my old 406.
By disabling the auto lights with PP2000 then they are effectively made non functioning so the auto lights are permanently off, even if you turn them on with the stalk.
The button on the end of the stalk has a copper ring underneath which can deteriorate, I believe it's fairly easy to replace - I can try to find some pictures if you like?

As a thought, I think if you put your ignition on position 1 ( radio works but no dash lights ) and press the button for a few seconds you also switch off the lights permanently - I'm not 109% on this though....

This copper contact ring you're talking about was actually broken on the other side of the stalk (MFD button) and I've repaired it by carefully adding some solder to the broken end, because I couldn't find a replacenent, and it's now working flawlessly. I can check the auto-lights side too if needed, but what should I look for? If the contact ring was broken, I shouldn't be able to turn on and off the auto-lights function itself.
Also the left side of the stalk could be harder to dismount because of the rotating end that turns on and off the lights manually (this is not present on the right side of the stalk since the 406 coupé doesn't have a rear wiper)

[Vincintosh]

Ok I've been really busy these days and since this is more of a "pleasure" car I usually don't drive to work (I have a 208 as a "work" car), the 406 has been sitting for like 10 days. Of course the battery went a little down (in fact when i turned it on, the starter sounded like it was struggling a bit) and also, while staying still in my garage the car was all dusty and I had to clean the windshield again. So, I don't know if this time I cleaned it better or if the battery discharge acted as a "reset" in some way, but somehow the problem just disappeared. The car is now flawlessly turning the auto lights on or off according to the ambient light conditions. I'm sorry if I wasted your time, but I'm happy to have one problem less... at least for now Thanks for your interest!

[Doggy]

Glad to hear it's OK now.
Don't worry about asking for assistance, we're always happy to help.

[GingerMagic]

Yes, glad it's fixed itself - French cars seem to do that sometimes..
As Doggy says, you weren't wasting anyone's time, the forum is here to help.

[Vincintosh]

Thank you very much. Well, ironically the problem reappeared yesterday, the lights had the exact same behaviour, but this time it happened in the early moning. I then took the car again in the late afternoon and the lights were still on, so I'm suspecting that it is related to the poor outside light conditions: i mean, at 7 AM and 8 PM the sun is already or still up, but it's not like 12 AM, you know. It's like the sensor struggles with recognizing slight light changes. It has never happened, but maybe something is getting old. I'll continue to watch how it behaves and then maybe find a way to adjust the sensitivity (I don't have a PP2000 kit for now, maybe I'll buy one or I'll eventually take the car to a local Peugeot dealer :/ ). I'll keep you updated!

[frog]

I also noticed that the automatic lights often stay on when the sun is at a very low angle. This morning around 7 am the sun was shining quite bright but at a low angle, the automatic light was on during my complete trip to work.

But if the sun is up high the lights are always off.

For me it is not so important. In fact I usually turn on the lights manually if the sun is at a low angle, for better visibility to the other drivers.