C70 mk2 - Electronic Nightmare - Errors / dashboard lights

[sbk1972]

Hi all,

Just drove home from the super market and my c70's electrics have gone haywire. Dash was flash lots of lights, rev countr working / not working. windows not going up or down. Park system erorrs.

So I checked the battery and that is 13v / charging at 14v

Tons of errors in my reader

6D0D - Control module initialistion of window
E001 - Control module communication faulty
DE42 - Communication with DDM control module . singal missing.

I cleared lots of faults but the above stay the one. windows are working apart from rear drivers.

Questions -

Where is the DDm located ? I waished the car last night and I wonder if water has got in somewhere. I had a similar issue with Ml55 and the cam bus went ballastic due to a plug half knocked out. Took me 4 months and removal of dash to fix that.

Where are the common spots where water / ecus meet ?

Simon

[pinballdave]

DDM is Driver's Door Module, and is the ECU box attached to the window motor in the drivers door. This is another one that would usually point to wiring problems in the loom to the drivers door. or the Dash/A-Pillar loom to the CEM.

The rear windows are controlled via the DDM, Each rear door motor is controlled via a LIN bus connection to the DDM, which is in turn controlled by the CEM over the CAN bus.

If you've been working on the door, and the plastic sheet that keeps moisture away from the door card is poorly sealed, then water may be able to get through to the wiring/modules on the door.

With your generic fault codes, you really need to know which individual modules are giving these errors. With VIDA all codes are prefixed by the module, your "E001 - Control module communication faulty" could be coming from anywhere, there are multiple modules that can give an E001 code. Is it a CEM-E001, DIM-E001, TCM-E001?

Also when "everything goes haywire", but the car returns to normal after stopping and restarting, it's the fault codes that turn up once and don't return after they are cleared out that can be really useful to determine where an intermittent fault lies.

[sbk1972]

Thanks pinball.

After work I plan to remove door card...AGAIN. Will be 19th time. lol. Will check connectors and loom for breaks.

Then I plan to tackle a Piller carpet / loom

Then I will check fuse box under glove box to ensure it isn't wet

Then I will pour 5litres of unleaded over it and burn it

Simon

[Teddy1975]

That 'fuse box' (CEM) under the glove box just so happens to be the brains of the car. There's a lot more going on there than a quick glance might indicate.

Best of luck.

[Bonefishblues]

I've been reading your threads. I know it was cheap but it does sound like you bought someone else's failed project

[sbk1972]

I think your right. I don't think I was told the full story about this car. Or but trying to fix one issue I've introduced lots of others lol

I've kept a log on costs and currently I'm not that much into it and could sell it for more, which I am considering if honest. My motivation is dropping I've got to say.

Simon

[Bonefishblues]

Sometimes it's the right call. Buy a well-sorted one and you're golden... And of course I know where there's one that meets the description

[Lancee]

Step back from it, take a deep breath (maybe, if you can, leave it for a few days ?), then come back to it with a logical approach. If you do crack it you will feel like the King of the World !

If it was cheap enough and you have the room to keep it and work on it, maybe treat it as a hobby project ? This may mean you need to buy another car to use in the meantime ?

I am loathe to suggest it but you could break it for parts, it sounds likely that you might get your investment back this way. Headlights, even used (uncracked) for these are not cheap.

I feel your pain. Buying a used Volvo with issues is a gamble, some you win, some you lose.

One thing that comes to mind is double check you have a good battery, that terminals are tight (good ground), and it might sound silly, but as it's now an older car, check all connections and the fuses for cleanliness/corrosion. I have pulled many a "grubby" fuse with a dirty blade, and have cured a long standing intermittent fault, one which cost the previous owner a lot of money trying to fix via a main dealer, just by cleaning the one relevant fuse.

And try not to introduce any further faults in the process !

Good luck, and stay cool ! And of course the above are only my opinions, interpret them as you will !

You probably need ViDA/DiCE to get to the bottom of this ?

[sbk1972]

Thanks Lancee

Youre right about standing back, and also faults do pop up due to previous work performed. I also have a Mercedes Ml55 and had a similar Cambus error on that. Took me 4 months, partial rebuild of the engine loom and driving without a dash to fix it :-) Im 50 now and the old motivation isnt as .... strong as when I was younger.

Ive re-traced my steps, ensured all connectors are cleaned and firmly reseated. Ive gone through the fuse box, inside and engine, Ive checked the loom / connectors where possible. Car seems ok today.

I have created an advert on Facebook, Ive priced it fairly and will see what happens whilst I work on it.

I did have to fix the headlights, turns out ballast had gone on the driver's side. Not a big issues to fix / replace. So far Ive done ;-

New brakes / pads / disks alround
New headlight ballast / new bulbs
Wire brushed all wheels components and painted with hammeright
Cleaned / oiled seals
Fixed radio - aerial issues
Fixed locks

SRS is on going. I reckon it's somewhere from door connector to airbag but Ive lost motivation for the time being. Out of inrested the lights on the dash are leds within the speedo as I tried to remove the bulbs :-)

I will leave it for the weekend and come back with fresh eyes

Simon

[pinballdave]

Originally Posted by sbk1972

SRS is on going. I reckon it's somewhere from door connector to airbag but Ive lost motivation for the time being. Out of inrested the lights on the dash are leds within the speedo as I tried to remove the bulbs :-)

Let's just say that I am aware of a rather similar dash with LED lights, fitted to a rather similar vehicle, where a replacement part couldn't be obtained in time for the MOT test, and so the warning LED was carefully un-soldered from the board, and then using very thin wires attached in parallel with one of the other dash warning LEDs, and stuck back in it's original location with double sided tape. This meant it lit up when the ignition was turned on, and then went out with all the other warning lights when the engine was started, and MOT tester was none the wiser.

Of course an easier bodge may be to fit a 'test' resistor directly to the SRS ECU and then disconnect the errant airbag.

These are the sort of cars I tend to buy (but no space for another at the moment). Something nice and cheap that the previous owner(s) have given up on trying to fix. I get to give the diagnostics side of my brain a good workout, and hopefully end up with a car I otherwise wouldn't be able to afford. If fixing it is beyond me, then it can be punted on for someone else to try.