Electrics: Is the CEM on my XC90 dying/dead?

[Simmy]

it sounds like your fault may be heat related was your journey on a hot day? i see clan also thinks it may be heat related iv seen on other fourms that some have fitted extra cooling for the cem with heatsinks and computer fans it would seem your problem is not unknown .search the mathews volvo site for info and xmodex for cem cooling

[Parknest]

Yeah, I'm aware of these possibilities and the jury is still out. I've had both my local specialist and Lukasz say that the faulty DEM might be the cause. It survived a trip to Costco in Oldham in rush hour traffic which included queuing for diesel. I need to run it continuously for at least 2 hours and 45 minutes to see if the problem comes back so I can't say for definite if the problem is fixed or not.

[Simmy]

costco oldham 5 min walk for me try the clive brook heritage club meet in huddersfield to get expert volvo info and advice for free they are held on saturday mornings. check the web site for meet details and dates

[Parknest]

Oh feck! The problem has come back to haunt me. I was 3 hours into a journey and the problems with the loss of most of the electrics reappeared. I was able to get home and I got the same error codes as before when I scanned it. I'm 95% convincned that the CEM is indeed faulty. I'll be speaking to the specialist in the morning and if he agrees, I'll be sending the CEM off to Lukasz for repair. The faulty DEM was a problem but it wasn't THE problem. I'm glad this has cropped up before the first outing for the caravan this year.

I'll keep you posted.

[Simmy]

how old is your battery and have you checked the output of your alternator volvos are well known for failing electrics low battery can throw up all kinds of gremlins it must be worth checking. before wrestling out the cem for repair. ps iv just looked at your scan tool print out it dose not seem to show voltage readings if voltage checks out ok then proceed with the cem ..when you clear these codes do all the same ones return straight away or later after driveing a good distance>

[Parknest]

It is the same problem as before with the same symptoms so I'm making the call on this one. It starts up on the button and the problem only happens after 3 hours of continuous driving. These are the fault codes I had when I scanned it last week:

ECM-A03B
ECM-A500
ECM-9210
ABS-0094
CEM-1D08
SRS-00D5

I was able to clear all thses codes and they will only come back when I start getting the symptoms. It is now with the specialist who will remove the CEM and I will send it off to Lucasz for repair.

[Simmy]

good luck with the repair . i hope this will bring an end to your frustrating problem keep us posted with the results i am very interested in the outcome .

[Parknest]

The CEM has been removed and I've sent it off to Lukasz for repair.

[Parknest]

I got the repaired CEM back yesterday and dropped it off at the specialist for refitting. Once that's done my troubles should be over.

[Simmy]

lets hope so iv followed this post for a long time let us know your out come.