Hi Gents,
since 2 years have a troubles with a Car's electronics.
Dashboard flashing (switched on/off), immobilizer let not start the motor, Speed control, etc. This happens for short times from 1-2 seconds til 3-5 minutes only.

Last week got a full stop - Dashboard is off, can't start the diesel - that's it. Everything else works perfect: all sensors (doors and interiors lights, central lock, key and light, electric windows, electric mirrors folding). This says to me that BCM is functional (or at least partly functional), Only the things that use CCD bus are off.
Some strange point - after I switched stand lights, a Dashboard and button illumination start work but for 20% of full power with very slight flickering.
BUT it can flash back to work for a second and then the odometer on dashboard stay on for few seconds.

Well, read lot of posts in russian, german, english: checked ground soldier on the Dashboard board, checked all electric schemes.
Checked the voltage on the Data Link Connector, actually 0,25V, at the Dashboard flashing it goes up to normal 2,5V.
Disconnected B23/P18 - no changes, where to look?
Have anyone a solution or the tip what else I have to check?

Please help, need a car very soon!

 

Oh, forget:
"Alarm Set" and "ABS" lamps are on.
I can start a Diesel, but immobilizer stop it after 3 secs...
Last day disassembled BCM and Junction Box, checked connectors and relais contacts - 100% OK, Connectors at PDC are also OK now.
After I've assembled it back (did not fixed Junction box on it's place) and connect battery - IT STARTS TO WORK!!!
BUT!!! After I've fixed Junction Box - same issues again! CABLE connection to PCM?
Could you help me please locate the PCM (and its connectors) on the 1998 2,5TD?
How else can I check the CCD Bus?

Many thanks in advance!

 

Found that SKIS on Diesel works direct to BCM... Where to look for the CCD trouble?

 

Any HELP, please!!!

 

The very first thing to do when you have "wierd" electrical issues, is to do the 'hard-reset' of all the micro processors by disconnecting the battery -ve lead for a few minutes. As there is a possibility of losing the radio-code, have it to hand.
If all faults are cured, check the battery is poor and sulphated -- substitute a known good battery to see if problems return or not.
If the hard-reset doesn't cure the problems, you've wasted no time or money.
There are lots of postings on this website how to look further into these electrical problems.

Leedsman.

 

Hi Leedsman,
Did all you suggested many times. Battery is 1 year old and full charged. No result.
will check again the cables...
But may be someone have a similar issue (Dashboard and illumination).
It is 100% CCD Bus ussue (or modules that connected there in), everything else on BCM (or managed by BCM) work good.

 

It does sound like a dry joint or cabling issue, do you have a oscilloscope to monitor the bus signals?

It's worthwhile looking at the waveform of the bus signal for interference or distortion, you can also try disconnecting other modules to see if one them is dragging the bus down.

Bus diagrams are here

http://1drv.ms/1c7pXkU

files 701802-6

Regards
Richard

 

Hi tfb,
thanks for support, I think it same way.
Did not tested cabling yet as the car is placed in the back yard and it's rainy there...
Have no oscilloscope but will check cabling and voltage at disconnecting connected modules.
Diesel model have few of its only. Radio, SKIM, Dashboard and overhead computer.
Have disconnected last two, voltage still same 0.24V should be round about 2,5V.
The pictires you shared are too small need to zoom more than 6400% just to understand what it is... do you have a better version?

 

additionally will try to connect BCM direct to B23/P34 connector (to overhead comp+dashboard) this will be easy to isolate the broken pipe

 

no sorry, the originals are in .svg format and for some reason the conversion to .pdf shrank them. but at max zoom they come back to A4 size.

I'll upload the .svg format as well

Regards
Richard