V70 Electrics issue - CEM, ECU or something else?

[Antroyd]

My first post on this forum so hopefully it's worded ok.

The following rather odd electrical issues all started happening at the same time on my 2006 V70 2.4D:

1. Ignition position 1 (which should be just stereo etc.) acts like position 2, with all the dash lights you would expect to see in position 2 (engine running)

2. When engine is running, turning the ignition back to position 1 does not stop the engine which carries on as though nothing had happened.

3. Turning the key to position 0 still does not kill the engine, though the stereo, lighter etc. does go off as expected. Even removing the key completely does not kill the engine, until after almost exactly 10 seconds when it does eventually decide to stop.

4. The windscreen washers no longer work - i.e. the pump not doing anything at all. Wipers are fine though.

5. The ABS warning light is constantly on with the message that the ABS system requires a service, which it doesn't.

6. DSTC Spin control has stopped working and will not engage.

7. The battery runs flat after several hours since there is something still live which should not be - I have to disconnect the battery every night to stop this. The battery is new and the alternator is fine, but this fault clearly suggests that even without the key in the ignition, the power is still being supplied to the engine or other parts of the car which are slowly draining the battery. The fact that the engine continues to run for 10 seconds would also suggest this.


I have sought professional advice from a Volvo Independent garage, and they were rather baffled but fairly convinced it was a CEM issue. Other advice I have had was that it might be the ECU.

So my question before I spend £1000+ fixing the wrong part is this:

Could these problems be caused by a faulty CEM?
Could this be an ECU issue instead?
Or could it be simply a faulty ignition barrel switch?
Or could it be something completely different?
Is there a way of diagnosing this to establish the exact cause?
Is a CEM repair worth considering or should I just replace with new?

Sorry for so many questions - I am a newbee at this forum thing.

If any of you knowledgeable Volvo experts could share your thoughts or experiences, I would be very grateful as I really can't keep throwing money at the problem, but the car is fantastic otherwise, runs beautifully and has only recently had a replacement gearbox and clutch, so I am extremely reluctant to get rid after all I have invested in it.

Thanks for your help people

[oragex]

Just my opinion, but I'm afraid this is the kind of issue that needs rather a hands on examination. It is not something common, if the CEM is at fault (usually on 04 and 05 years) it will behave differently. May still look at the module with a flash light, search for any traces of water (dried or not). As for the ECU I don't see how it would cause these, normally the ECU (or ECM) also controls the engine. Maybe unlock and pull the steering all the way down and towards the seat, the pop the upper plastic off the steering column, and look inside. The key barrel has sometime issues with the key not turning, a chance the previous owner did some getto fix around it ? I also suggest having the key in POS II when reconnecting the battery, and indeed try not to let the battery fully drain, this may cause some other (annoying) issues. I did use by the past a battery switch like such on the '-' pole https://www.ebay.com/itm/17mm-Car-Ba...c66377fe22a806

[gelertd]

I had a battery drain linked to the radio. I suspected it might have been the CEM causing the drain.

A few weeks later I noticed that both front side lights didn't work and shortly thereafter began to get random, bizarre messages (anti skid, ABS faults, engine faults) showing on the DIM. Classic symptoms of a faulty CEM.

Sure enough after removing the wipers, scuttle cover and wiper motor assembly I was able to access the top of the CEM and found green crustys around some of the terminals on the CEM. On your model year, water is able to get into the top of the CEM and cause corrosion. Volvo do an improved waterproofing kit and can supply ready wired replacement multiplugs if the corrosion is really bad.

I removed the CEM and sent it to Lucaz at volvodiagnostic who was able to repair the module but said the corrosion had gone pretty deep. After installing my original repaired CEM and clearing the various multiple codes all was well. No battery drain, everything works again as it should.

Lucaz advertises on the forum (see 'Problem with ETM DIM or NAVI??? Cheap services here' on traders section) and I can highly recommend his work. At the time of writing he charges £150 to repair your faulty CEM.

[gelertd]

If your V70 hasn't got the updated waterproofing kit for the CEM the following may be helpful.

The updated waterproofing kit consists of:

30765127 Bellows
30728861 Seal
31300077 Flange Screw (4)
I paid £34.32 at my local main dealer (Riverside Hull) for these parts (March 2018).

Volvo have a service bulletin for the issue but the parts guy didn't know of it so had to speak to the master tech who, having done a few of these replacements, pointed him in the right direction to locate and then order the parts.

You will need 2 cable ties to seal the bellows.

Lukas ('spokoluzik') mentioned in my earlier post (under Traders Section see 'Problem with ETM DIM or NAVI??? Cheap services here'), has a website.

http://volvodiagnostic.com/

[oragex]

Which year was the car in the above comment ?

[gelertd]

It's a 2006 XC70