xantia hdi bsi unit

allanmc · Post by **allanmc** » 03 Oct 2011, 16:21

Hi, back again an auto spark has said that I need a new BSI unit priced this from Citroen price £250 does it have to be a new unit or can it be fixed, contacted french used spares in England they have a kit for £ 100, not knowing much about elec. any sugestions.
allan

DickieG · Post by **DickieG** » 03 Oct 2011, 16:31

Xantia S2s don't have a BSi as such but they do have a CPH body computer, what is the problem with the present one/your car?

allanmc · Post by **allanmc** » 03 Oct 2011, 16:54

DickieG, been on a few times about my problem which is the battery more or less drains if the car is left overnight auto spark has diagnosed the body computer unit he says I will have to buy a new one but I was hoping there might be another option what do you think,
allan

Post by **RichardW** » 03 Oct 2011, 17:09

Battery capacity on an HDi is what 85Ah? So you can drain it in 10 hours say = a current of about 6A (assuming it's flat without giving the full reserve). On 12V system, 6A = 72W, more than a head lamp bulb. If the body computer was really leaking that much current it would be red hot. I'd be looking elsewhere - maybe the CPH is switching something on? But with that current draw it ought to be hot! Leave it overnight and see if anything is hot - alternator, starter, the electric water heater down the back of the engine, one of the cooling fans, the blower in the car, any of the doors around the lock area.

allanmc · Post by **allanmc** » 03 Oct 2011, 19:14

Richard, thanks for your input if I might explain if the car is left for two nights it wont start after one night the batt drops from 1250volts to about 1175, anyway after your reply I conected the batt. so in the morning I will see if anything is hot, by the way daft question what is the CPH ,I am getting confused about what unit I am talking about, phoned Citroen they said it could be the BSI, £250 thats the one that puts the car to sleep after 3 min. I thought it was called the Body Computer unit but I will let you know how I get on.
allan

DickieG · Post by **DickieG** » 03 Oct 2011, 19:21

I'd bet on the cooling fans running after the engine has been turned off as a bulb illuminating will be obvious, if it was a glowplug or the cooling system glowplugs they would have blown by now. One other item would be the heater fan. IIRC there were reports of 406 Peugeots suffering from this a few years ago and as 406's and Xantia's have a lot in common it must be a good place to start.

A simple way to start diagnosis must be to simply sit in the car after it has been locked and listen for the noise of electrical items running/being turned on by relays etc

Post by **CitroJim** » 03 Oct 2011, 19:21

The CPH is the Xantia term for the box of tricks that hides behind the passenger airbag and carries out the following functions:

Alarm, interior lights, central locking, transponder control (key programming) and no doubt other minor tasks..

As far as I know, it does not make the car sleep as say the BSi in the later C5s do...

The battery drain could be accounted for by the alarm going off. If the hooter is silenced then the headlights and indicators will still flash and thus possibly drain the battery...

Normal standby current drain when everything is off and the car is at rest is around 50mA. I've stood a Mk2 Xantia for over a month with no problems...

citroenxm · Post by **citroenxm** » 03 Oct 2011, 20:16

DO NOT get confused by the Body Computer and the Fuse Box on the Xantia.

They are in two completely different places!

The fuse box in ALL Xantias is just that and always in the same place.. behind the fold down flap above the Accelerator Knee (RHD cars)

However, the "Body Computer" which is NOT a BSi as said above is located behind the dash along with the CL reciver box and the traffic Master Box..

You can gain access by removing the glove box and passenger air bag... there up the top aobve the heater duct you will see all three "Black" boxs stacked ontop of each other.

Ive NEVER heard of a body computer or Xantia Fuse box causing a draining problem at all...

Paul

allanmc · Post by **allanmc** » 03 Oct 2011, 20:34

Right I went and checked there is nothing running after I leave the car no alarm lights but still if the car is not started for two days it wont start I know exactly where the fuses are some in the cabin and some in the engine compartment, so you say you have never heard of a Xantia body computer or fuses draining the battery so can you tell where to look, I,ve asked on the forum for some months about my key plip not working all the time might this be relevent
allan

citroenxm · Post by **citroenxm** » 03 Oct 2011, 20:39

Ive not been following your problems to be honest..

Faulty altinator...? They can develop a fault that can drain the battery...

Unfortunally you see, with a SERIES 1 TD Xantia dooing the same thing. But the dillema I have is the car has HAD new altinator... and theres no interior lights left on either..

PILP no working? Sounds like it may need a re-sync with a Lexia. Have you looked to be sure the surface mount switchs have not broken off??

Paul

Post by **myglaren** » 03 Oct 2011, 20:45

IMO you need to connect an ammeter between battery positive terminal and positive lead connection, determine what the current drain actually is and then yank fuses until the drain is eliminated.

Start with a high setting initially and reduce until the needle is more or less central if using an analogue meter - same with a digital, use a range that gives a reading in approximately the centre of the range.

If as Paul says it is the alternator then that could be eliminated initially by disconnecting it. Probably easier than accessing all the fuses one by one.

addo · Post by **addo** » 03 Oct 2011, 21:59

Nobody seems to believe alternators can do this. Odd, this. A collapsed diode quite happily lets current through to ground.

Post by **Peter.N.** » 03 Oct 2011, 22:27

They certainly can but will get hot.

Peter

torq · Post by **torq** » 04 Oct 2011, 15:27

A bit off topic but. I have a 01 citroen relay 2.8hdi that kept the oil pressure light on even with the ignition turned off. Replaced the alternator and the problem was gone! My conclusion was that as the oil pressure switch wire was beside the alternator charge wire that the faulty alternator was somehow energising the pressure switch.

I'd go with the multimeter and pull out fuses one by one method of diagnosis.

allanmc · Post by **allanmc** » 04 Oct 2011, 16:48

Hi, been back at the car with the multi meter again and when I set it to 10amps and change the red lead to 10 amps it just blows the fuse in the meter could this be significant
allan