C5 Mk2 Lost Automatic Dipped and side light function

[masood_ilyas]

This refers to Citroen C5 2.0hdi Mk2 with 56 Number plate, regularly serviced and has 60200 miles on the clock.
After 5years of fantastic service my beloved C5 is now begining to show tantrums.
First it lost automatic interior light control on opening door, that was bearable but then recently it stopped "Auto Switching" the side lights and dipped beams.
Manually these can be controlled fine, so lamps are ok. All windows and radio works fine too.
Using Menu control (Radio display window) the parameters settings do change from enable to disable to enable light controls but this does not actually happen!.
Battery was replaced six months ago at Halfrauds, can be assumed ok as there are no starting problems.
That was scary to watch as it was done by Halfraud Technician with Engine running!!! ( Never go there again )
I read somewhere that these odd problems can be cured by resetting the BSI box.
The trouble is that I am not sure if it was genuine advice as the process quite honestly was bordering on comical
(e.g Leave the window down and wait, do not open doors, disconnect battery and wait 30 minutes for total discharge etc).
The PSF box and presumably the BSI box is sealed in resin for life so no chance of changing a relay.
I do have a Lexia machine but with novice skill level with an L-plate attached.
At times like this I do miss all my previous Xantias!!!!
Any advice on diagnostic process will be most appreciated.
Thanks
Masood ILYAS

[Hell Razor5543]

The BSi reset is (in effect) letting the car shut down all the various electronics properly. Think of it in the same way as a PC. Do you tell the PC to shut down, or just pull the plug? The reset can clear down glitches that (because the electronics don't really turn off when the key is removed, they go into standby) would still remain in the systems with the ignition off. Here is the link to the reset;

BSI Reset / Battery Disconnect / Reconnect Procedure

[myglaren]

It is surprising what a BSI reset can do.
Can you be absolutely certain that your system voltage is correct as that is usually what lies behind these shenanigans.

If possible remove the battery and charge it overnight to be certain, then check voltage before fitting, on car and with engine running.

What was the reason for the battery renewal? - if it isn't charging properly it could be due to corroded or loose terminals.

[Stickyfinger]

BSI reset in not comical, you are rebooting (basically) a number of PC's on a network. Eg BSI talking to various ECU's around the car that control all the sub-systems such as AirBags ect ect.

Follow the procedure to the letter and you may solve the problem.
As advised above, take the opportunity to charge the battery over night.

[Mdon]

I've never had to do the bsi reset, however I've never read you have to leave it 30 minutes with the battery disconnected. This is the bsi reset I've seen posted several times

Battery Disconnect / Reconnect Procedure

[masood_ilyas]

Thank you all for the advice, I will give all the C5's PCs a reboot over the weekend and update this entry.
The battery was replaced last year when the original one failed after about 9yrs of service.
I hope my next job after this one, the cam belt change will not require any BSI actions.

Masood

[Stickyfinger]

It will as you should disconnect the battery when you change the belts.
( It will ensure you (or a helper) does not turn the engine by error when the bet is off )

[Mdon]

To be honest, removing the battery and the connecting it shouldn't need a bsi reset on a MK2, only the Mk1s threw wobblers when the battery was removed. I've had the battery off a couple of times and I've now replaced it on my 57 plate Mk2 all with no negative effect or bsi resets. I suspect it may be the light sensor for your automatic lights but it's worth trying the free and easy stuff first like the reset.

[GiveMeABreak]

Like any other computer hardware a reboot and or a power cycle will often cure problems. Same with the software that can sometimes remain memory resident. The BSI rest process is also recommended by BBA Reman and feedback from owners is a testament to the procedure's ability to eliminate some problems. Personally, I can say that it has solved many issues on both my Mk1 and Mk2 C5s and the C3

[Paul-R]

The auto headlight function on my C5 stopped working about five years ago. One day it was working and the next day when I was going through some tunnels I realised that it wasn't. TBH it didn't worry me and I haven't bothered to fix it.

One thing that may be relevant is the automatic wiper function if you have it fitted. Does it work properly? On my car it never did: slow to respond to light rain and then flailing away madly when the screen was dry. It was so annoying I turned it off using my Lexia and have never missed it since. In retrospect, maybe they were both symptoms of some trouble that affected both sensors in the area behind the windscreen where the rear view mirror is. My car has an auto dipping mirror but if yours in the standard mirror it may be easier to get at.

[RichardW]

To be honest, removing the battery and the connecting it shouldn't need a bsi reset on a MK2, only the Mk1s threw wobblers when the battery was removed. I've had the battery off a couple of times and I've now replaced it on my 57 plate Mk2 all with no negative effect or bsi resets. I suspect it may be the light sensor for your automatic lights but it's worth trying the free and easy stuff first like the reset.

Not really... all PSA cars post about 2002 (and some earlier) use the BSI, and care needs to be taken when taking the battery off. Whilst you have got away with just taking it off, many others have not, and all sorts of maladies can result, eg no locking, immobiliser codes lost etc etc. TBH a lot of bollox is spoken about BSI reset with taking it off ages and touching the cables - if you let the BSI go to sleep (about 3 mins) and then take the battery off, and then let it wake up slowly, with some light load on it (eg lights) before cranking the engine, then it will re-start OK. If you Lexia a car post battery change you will most likely find a fault in the BSI for unexpected re-start.

[masood_ilyas]

Today on a relatively less windy day I managed to go through the BSI reset routine.
The dipped beam came back fine but to my surprise the side lamps did not.
I found both lamps were dead, how odd both taking a hit at the same time.
Another surprise was the radio did not loose its setting, all channel data was safe.
For the moment I am happy it is now working fine.
On an earlier note when I mentioned the BSI reseting was comical, it was because it reminded me of a news conference held in the early 90s by Chrysler or Ford when their chief executive was asked why their cars are becoming more expensive whereas Bill Gates computers were getting cheaper as time went on. His response was, if we made cars like his computers then our cars will have a mind of their own, stopping for no reason. Some functions will stop working and you might have to get of the car close the door get back in and start the engine again.

Thanks to all of you who offered their advice.

Masood

C5 Mk2 2006
Xantia 1.9td 1999 On the drive, SORN 2012, Still reluctant to recycle it.
Xantia 1.9TD 1997 Auto.........Probably a Fridge by now
Xantia 1.9Td 1994 Recycled

[Stickyfinger]

Windows in a car BSI......now that IS funny

[dnsey]

Sidelight bulbs are a weak point on these, and fail regularly. LED replacements are a good idea, particularly as they're a bit awkward to fit.

[GiveMeABreak]

Easy to fit front LED sidelights on a Mark 2 facelift with Xenon bi-directionals. Cap off, 2 fingers in and pull out wire with holder. Both swapped in 5 minutes.