CEM or DIM?

[Big Ted]

I've had an intermittent fault on my D5 163 XC90 (53 plate)
It's just come back after 6 months of not being there & I've a service due next week, so I'm hoping to get some advice before it goes in.

The car loses power for a split second, with a clunk from the front.
At the same time, the Dashboard & radio lose power, with all display's going blank.
Within a blink of an eye, the car is back to normal, though I've got a few warning lights lit, namely a SRS warning light.
A few miles further down the road, the same happens again & so on.
Then, after about 30 mins of this, the car repeats this, but then goes into "no power" mode & limps along at 2 mph. ( All dash is off, windows won't work, indicators/hazards all not working.)
The Warning message helpfully states - MAJOR issue - STOP ( or something similar)

I let the car cool down & 2 hrs later, good as gold & back to normal again.



I've done some searching & found similar tales, which point at the CEM, but also one or 2 which point at the DIM.
When this occurs, I've noticed the dashboard module is extremely warm, even hot.

The CEM appears to be ££££ to replace so I'm keen to see if there's a fix or workaround.

Does anyone have any experience in a similar fault & any guidance as to what to look out for in terms of a. replicating the fault to show the garage or B. fixing it to save ££££.

ta,
Ted

[lesk]

had a bad experience when water ingress (the fault volvo deny) due to bad design fried my cem which in turn fried the rem as well. Total cost aproaching £2k with a little help from rufe and the excellent BVS. My systems were 'anti skid service, and no parking sensors plus various funnies with the radio etc.

lesk

[kay11]

Originally Posted by Big Ted

I've had an intermittent fault on my D5 163 XC90 (53 plate)
It's just come back after 6 months of not being there & I've a service due next week, so I'm hoping to get some advice before it goes in.

The car loses power for a split second, with a clunk from the front.
At the same time, the Dashboard & radio lose power, with all display's going blank.
Within a blink of an eye, the car is back to normal, though I've got a few warning lights lit, namely a SRS warning light.
A few miles further down the road, the same happens again & so on.
Then, after about 30 mins of this, the car repeats this, but then goes into "no power" mode & limps along at 2 mph. ( All dash is off, windows won't work, indicators/hazards all not working.)
The Warning message helpfully states - MAJOR issue - STOP ( or something similar)

I let the car cool down & 2 hrs later, good as gold & back to normal again.



I've done some searching & found similar tales, which point at the CEM, but also one or 2 which point at the DIM.
When this occurs, I've noticed the dashboard module is extremely warm, even hot.

The CEM appears to be ££££ to replace so I'm keen to see if there's a fix or workaround.

Does anyone have any experience in a similar fault & any guidance as to what to look out for in terms of a. replicating the fault to show the garage or B. fixing it to save ££££.

ta,
Ted

My XC90 T6 had the same problems, when the car got hot on a long run. 2 weeks ago started again on motorway trip and then shutdown altogether. My CEM is the problem and is being looked at to see if it can be repaired as a new one is about £520. + Labour,vat. After reading similar problems, it keeps coming down to CEM being at fault. but it is difficult to diagnose when you take it to the garage as there is no fault or they cant replicate the fault. have the CEM taken out and looked at by an electronics person. could be something simple like dry soldering joint. It will be an expensive repair at the dealer. Try finding an independent volvo garage.

[Big Ted]

One thing I've since noticed, is my "1" button on the radio no longer works.
I'm assuming this may well be tied into the CEM as I believe it may be linked?

How easy is the CEM to get at & could I remove it, have an inspection & refit it with no issues?