Xemodex CEM rebuild

[Forkster]

My CEM has been giving me overheating issues for a number of years. For around $600, if you send them your old CEM, they'll give you a rebuild with a heat sink on the MCU.

I'm thinking that if that's all they're doing, I might even go a step further - put a heat sink AND a small 12v fan myself.

Question - Am I better off just enhancing my CEM or should I just send my CEM to them and get their improved model back? Is there a chance my CEM has been damaged from the overheating issues?

Thoughts?

[JRL]

CEM is the central electronic module, they cannot rebuild that

[billr99]

CEM is the central electronic module, they cannot rebuild that

Apparently they can (http://xemodex.com/technologyimprove...-cem-for-volvo). Or at least claim to. But logically if they are able to pull all the written data from the original and write it back onto a rebuilt one, it's not rocket science. All a matter of having the proper kit to do the job as well as the expertise. Have to wonder why Volvo isn't catching on with this and either offering rebuilds via their parts network or reducing their ridiculous pricing on new units to some level that could be deemed competitive.

Cheers,

Bill

[Forkster]

Both of you are correct - they don't rebuild them - just enhance them. Take a look at the heatsink they put on the main module.

I'm thinking maybe I need that and a small fan blowing on it (which is easy to do since the main fuse panel is just above the CEM).

What do you guys think? Just send it off to them to replace or enhance it myself?

[mapper]

non of these module repair places do any rocket science, they just know where the weak points are in the modules and "enhance" them. Usually it just requires some resoldering. We pay for the experience and research not the the work.

[cattlecar]

What are the issues and why do you believe it to be overheating?
Just curious. I have had cars with some lighting that would quit at odd times, not necessarily after a long time with ignition on or in hot weather. I never connected these failures with overheating.

[Astro14]

I can do a lot of things myself...but this is a case in which I would pay for expertise...if it were actually broken...

More important, though, is the answer to Cattlecar's question...why do you think you have a problem? What are the symptoms?

[Forkster]

The CEM is the bridge between the low and high speed data buses on the P2 Volvos. There is a known flaw in the design that if it overheats (and mine does) it causes weird electrical issues.

1. After running the car for more than two hours you'll get an alarm left rear passenger door open. U open and reclose it and carry on.
2. Short while later it'll happen again. This time transmission will thump indicating limp mode.
3. Short while later the car will go 'nuts' - a bunch of alarms will appear - brake booster failure ECM failure ETM failure etc etc and then the entire dash goes dead including lights turn signal climate spedo etc
4. U pull over and turn off car. U then wait a while (cause everyone is freaking out) and turn the car back on. Then the ole srs airbag failure alarm but that's it
5. U get a good scanner and it reports all kinds of communication error messages with a variety of components but the CEM shows a fault code.

That's the indication the CEM main module is overheating. These guys offer a mod to your CEM to prevent overheating but if your technically handy you can do it yourself if you think the CEM hasn't been damaged from the heat.

[coflynn]

If you want to get a small heat sink, use http://www.digikey.ca/product-search...752?k=heatsink . Under "Attachment Method" select "Thermal Tape, Adhesive (Included)", select the "In Stock" checkbox & hit filter. You'll then need to filter on the proper size. If you aren't 100% sure buy a few, they are ~$2 each or so. If you are in the USA change digikey.ca to digikey.com . I would get the size by just measuring the actual module.

BTW if it works be sure to post details of which part you got!

You could find a little fan from Digikey too if you want. Shipping is $8 and you'll get it the next day, so it's basically not even worth trying to hunt around locally when you can get the specific part you need.

[wsp310]

Ed,

Are you sure it's the CEM and not the DIM, which is the computer board behind the gauges. There are several videos showing issues with the DIM. I'm having the DIM issues and have pulled it apart and resoldered one area that's often mentioned. The same company also rebuilds the DIM. In their information, they mention replacing "chips" that were marginal from the begining. That makes sense when you think of how many of us have "modified" our personal computers over the last 10 yearswith memory, chips and graphics. From what I've read on this and other sites, there is also an issue with the soldering on the boards and over time the solder weakens and causes electrical intruptions. If they didn't charge almost $100.00 for shipping from here in the US, mine DIM would already be on it's way.

FWIW,

John