Interior light fault

[Stokie]

Hello all,

First post on here - and first time Citroen owner - so at the bottom of a fairly steep learning curve!

I have a problem with my interior lights which I’m struggling to get to the bottom of - no end of searching has found me the answer yet!

When I took ownership of my van (2011 M59 1.6HDI) a month ago, the interior lights didn’t work at all, but the front one had fairly obvious signs of rust inside the lens. I took it out to find that the internals were rusted to pieces - caused by the aerial leaking. I’ve since replaced the aerial, using a good dose of silicon mastic whilst re-fitting it, and have replaced the front interior light.

The problem I now have is that the interior light will only work when the switch is in the ‘constant on’ position AND the ignition is on.

In ‘doors open’ mode, the light doesn’t work at all, and with ignition off it won’t work at all either. The light in the rear works in exactly the same manner.

I’ve checked fuse 22 and that seems fine. I’ve also done a BSI reset (which brought my remote central locking back to life) but didn’t sort the interior lights. I’ve also had a browse of the wiring diagrams but can’t see anything else obvious to check.

I’m guessing the door switches are OK as both front doors, the sliding door and the rear door all come up as open in the central display when they are opened.

I did read a thing on a Peugeot forum about a reset procedure which requires holding an interior light button on for a period - but that button doesn’t appear to exist on a Berlingo - I did try holding the central locking button in but this just appears to enable/disable anti-hijack locking.

Obviously the bulbs in both units are ok as they will both light when switched to constant on with ignition on.

I’m lost with this one - I can’t see a fuse that is specific to ignition off and everything else seems to function.

I don’t have diagbox - this seems the next logical step, but I wondered if anyone has any ideas before I spend money on this kit.

I’d be really grateful of any suggestions - I’m guessing the water ingress and rust at the light has either damaged or caused part of the BSI to go off line, but would have thought the reset would kick that back in…

All ideas gratefully received!

Thanks,

Andy B.

[Sol]

The interior lights are directly powered from the BSI main circuit board. If the water ingress to the light has damaged the BSI circuitry then a reset won't resolve that unfortunately. It's a bit like spilling water into your PC, it's hard to guarantee no actual damage has occured and from what you say, looks like it has.

The door switch modules are built into the locking mechanism and those signal the BSI, it then in turn, puts the lights on or off depending on the signal from the door locks. Diagbox may help you find the code if one is generated, or test the system but if it's blown, it's not going to be easy to resolve.

I take it this is a Berlingo First van, as the 2011 is usually a B9.

I've attached some official schematics, they're B9 but the interior lighting will be near identical between both models. 

  Passenger Lighting 1.pdf (Size: 132.89 KB / Downloads: 19)

  Passenger Lighting 2.pdf (Size: 295.26 KB / Downloads: 13)

[Stokie]

The interior lights are directly powered from the BSI main circuit board. If the water ingress to the light has damaged the BSI circuitry then a reset won't resolve that unfortunately. It's a bit like spilling water into your PC, it's hard to guarantee no actual damage has occured and from what you say, looks like it has.

The door switch modules are built into the locking mechanism and those signal the BSI, it then in turn, puts the lights on or off depending on the signal from the door locks. Diagbox may help you find the code if one is generated, or test the system but if it's blown, it's not going to be easy to resolve.

I take it this is a Berlingo First van, as the 2011 is usually a B9.

I've attached some official schematics, they're B9 but the interior lighting will be near identical between both models. 

Hi Zion,

Thanks for that - yes indeed a late First van. Thanks for the schematics - I'll do a little more poking about then I can see that I'm going to have to get my hand in my pocket! it does seem strange that there is a working feed with ignition on, but nothing else - you'd almost expect all or nothing if the BSI was damaged, but then I guess with an ECU anything is possible.

Will report back if I get anywhere.

[Sol]

Yeah you'll find there are several outputs to the lighting module in the roof from the BSI, the switches ground sense wires to the BSI and before the lights go on, the voltage at the pins is 8V, then when the BSI powers the lights they go to 12V, it is a weird arrangement. So the main switching voltage must still be there while the door sense line may be down.

I would try a replacement lighting unit at the roof as there are so many web-like connections inside it, that corrosion could be causing issues. Check the pins at the multi plug, and maybe use a brass brush (with the battery off) to clean the pins.

Also and less palatable, is the possibility the water followed the wires down to the BSI and corroded the plugs on it...or even entered the casing.

[brajomobil]

Maybe you have to reset BSI outputs.
Here is more info: https://www.berlingoforum.com/thread-19100.html

Best regards,
brajomobil

[Stokie]

Bonanza - fixed!

I’d replaced the front interior light a while back, but it still didn’t work. I’ve just had a look around the connectors and all seemed well so carried out the BSI output reset and hey presto - sorted!

Thanks for all your help chaps!!

[Sol]

Nice one. I usually bleat on about a BSI reset and forgot today until Brajomobil correctly suggested it, just goes to show eh.

[Stokie]

No worries!

One other thing I have noticed is that the light on the central locking button now lights up when the doors auto-lock.

It’s like Christmas has come early!

Thanks again.