2003 Petrol -- BSI diagnosis: water ingression

[NewMaldenBlue]

Heavy rain while parked a few weeks back resulted in major issues:

Central locking not working.
Turning ignition on gives:
Dash board lights on all over the place.
Windscreen wipers and side lights come on.
Engine turns over on starter but no spark.

From other posts and a diagnosis at at an "AA approved Citroen service center" (£111 ouch) it appears to be water ingression.
Purchased vehicle last October for £900  -- Wheelchair conversion estate 

Solutions:
1.  Replace BSI -- garage quoted £689 with no guarantee  -- not appropiate
2.  Try to service the BSI unit -- garage diagnostics have left the unit "ad- hoc", I managed only to check fuses and try the "BSI reset".
3.  Replacement used BSI -- have been told if I get unit with the same number then it is plug and play.
4.  Scrap the vehicle to cut my losses.  -- Have private parking and it is SORN for as l long as I like.

Will try option 2  first and will post pictures later when I crack the BSI open and attempt to service. 

Just two questions for starters:
The BSI is next to the steering wheel of course.  Under the bonnet is another unit.  In a petrol engine is this just a fuse box?
Hayes manual is available for around £10 - £20 is that of any use in this case?

Will add signature later, but first need to make two posts.........

[Sol]

The BSI is under the dash, up above the pedals on the M59. The engine bay box is a fuse box (1 of 2) and the BSI has an onboard fuse box also. The engine ECU lives in the firewall at the back / inner wing but is a slave to the BSI and only controls basic engine functions like injection and fan.

Once water gets in the BSI, usually not repairable but possibly could be by swapping the top PCB from an identical unit. A full BSI can't just be swapped into your car no matter what the numbers are on it, has to be virginised or the car would fail to start even in a working vehicle. But the numbers do have to match anyway - so they were half right. It's a full on computer and controls everything else in the car.

The BSI also contains the Immobiliser. Once virginised, has to be re coded to the car using DiagBox - nothing else can do this.

[NewMaldenBlue]

Thanks for response Zion. Was wandering if or where the ECU was located.

Got this advice from an old friend regarding the BSI -- cannot do any harm as it stands.

"I would suggest drying it out - can't hurt and may work. If it's
possible to disassemble then take all the plugs and connectors off
(take photos before) and clean the metal surfaces where possible with a
hard ink rubber and then blow dry with hair dryer (keep below 60C) for
10-15mins. Leave in a warm place for 48hrs and reassemble ensuring to
tighten & wriggle all connectors. I did this with my Clio and saved
~1000 euros for a new ECU."

[Sol]

Excellent advice there mate, it could save you from a heap of grief. Take the chance to charge the battery fully while the BSI is off, as it should be removed with the battery disconnected and refitted before the battery goes back in.

[Tomcat3]

Take the wiper arms off and lift the scuttle tray and have a look to see if the drain holes are blocked. The water should run down from the top inner corner of the wing in the scuttle and out at the bottom of the wing by the door opening. The top scuttle drain is usually blocked with years of dirt and leaves so water builds up and finds its way down the loom in the end to the BSI. The BSI is behind the pull off panel by your right knee. There is a thread on here somewhere that shows how to separate the two halves of the BSI.

[NewMaldenBlue]

Thanks. Will charge battery. And with luck will address the suspected water ingress culprit; think I will get hold of the Hayes manual.

[NewMaldenBlue]

Disconnected the BSI (The garage had left it extracted from the diagnosis) and it is sitting on my desk.  All ports are colour coded Noir, Blanc, Gris and Vert.  There are 8 tags to to push down to pull the thing apart.  I will venture to start with the 2 tags at the back.  Possibly I will wait for an extra pair of hands this weekend. 

Below are a couple of snapshots before I start the disassembly. Lots of cooling slots on top where water can get in:

                             

[NewMaldenBlue]

Below is the BSI split open. (Just bent the tags over the hooks -- one of the tags broke but that is the least of my concern)   No water damage is visible so far, but will continue to treat as such.  Second snapshot shows two circuit boards attached;  I assume these can be pulled apart, but would prefer some confirmation.  The top board is mainly fuses, it has two connections, both 16 pin, to the bottom board which has all the circuitry.

                             

[ffrenchie]

I posted a couple of weeks ago after having central locking problems. The BSI splits leaving the black blocks and pins on the bottom board. They do not come apart or go back together easily  you need some force. I used a thin wood chisel to split them as anything else was too flexible.

 

[NewMaldenBlue]

Thanks ffrenchie -- gave me confidence to use brute force.  Pulled on one side until the assembly cracked creaked then on the other, repeating a few times until it separated suddenly.
The printed circuit board (pcb) is about 3mm thick and robust so I think I have got away with this.  
Have ordered electrical contact spray cleaner and will pick up an ink rubber as suggested.  

Can see no sign of water ingression but may as well proceed under that assumption.

1.  Clean both boards, dry them, partially re-assemble (this may be harder than separating the thing), spray all external contacts.  
2.  Could test resistance of relays as related in ffrenchies recent post.
2.  Meanwhile charge battery.  
3.  Plug and play -- Iff successful then re-assemble the BSI into the shell and test again -- will disconnect battery in between of course.
4B  One never knows -- place the BSI back into its home.
4A  Clean up the wiper scuttle drain......