Volvo Car Forums


Reply
Thread Tools Display Modes

2005 XC90 CEM corrosion

 
Boris Mohar
Guest
Posts: n/a
 
      06-10-2009

From 2005 XC90 CEM

A Volvo mechanic showed me this bit of insanity. The CEM1 circuit board
sits on top of CEM3 circuit board and they are soldered to each other via
header pins. CEM3 is conformably coated but CEM1 is not. The difference due
to exposure to elements is obvious. What possessed Volvo to protect one
board and not the other?

http://www.viatrack.ca/Misc/CEM1.JPG
http://www.viatrack.ca/Misc/CEM3.JPG

--

Boris Mohar


 
Reply With Quote
 
 
 
 
GlennK
Guest
Posts: n/a
 
      07-10-2009
On 10/6/2009 2:32 PM, Boris Mohar wrote:
> From 2005 XC90 CEM
>
> A Volvo mechanic showed me this bit of insanity. The CEM1 circuit board
> sits on top of CEM3 circuit board and they are soldered to each other via
> header pins. CEM3 is conformably coated but CEM1 is not. The difference due
> to exposure to elements is obvious. What possessed Volvo to protect one
> board and not the other?
>
> http://www.viatrack.ca/Misc/CEM1.JPG
> http://www.viatrack.ca/Misc/CEM3.JPG
>

The problem is water leaking in through the top cover on the cowl that
was not correctly sealed @ the factory. When I replace the CEM I use a
good glue to make sure that there is no water egresses in the passenger
compartment near the CEM
Glenn K
Certified Volvo Technician 2008
ASE Certified Technician 2008
 
Reply With Quote
 
 
 
 
James Sweet
Guest
Posts: n/a
 
      07-10-2009
Boris Mohar wrote:
> From 2005 XC90 CEM
>
> A Volvo mechanic showed me this bit of insanity. The CEM1 circuit board
> sits on top of CEM3 circuit board and they are soldered to each other via
> header pins. CEM3 is conformably coated but CEM1 is not. The difference due
> to exposure to elements is obvious. What possessed Volvo to protect one
> board and not the other?
>
> http://www.viatrack.ca/Misc/CEM1.JPG
> http://www.viatrack.ca/Misc/CEM3.JPG
>



That is strange.

The corroded one looks repairable though, I've fixed pinball machine CPU
boards that were in much worse shape from the memory backup battery
leaking all over them. Vinegar wash followed by a careful scrub with a
brass bristled brush can work wonders.
 
Reply With Quote
 
Randy G.
Guest
Posts: n/a
 
      07-10-2009
Boris Mohar <(E-Mail Removed)> wrote:

>
>From 2005 XC90 CEM
>
> A Volvo mechanic showed me this bit of insanity. The CEM1 circuit board
>sits on top of CEM3 circuit board and they are soldered to each other via
>header pins. CEM3 is conformably coated but CEM1 is not. The difference due
>to exposure to elements is obvious. What possessed Volvo to protect one
>board and not the other?
>
>http://www.viatrack.ca/Misc/CEM1.JPG
>http://www.viatrack.ca/Misc/CEM3.JPG


I would head over to the local electronics store and pick up some
products meant for such application- a board cleaner and there should
also be a spray available to seal the surface from moisture. be sure
to tell them that it is an assembled component and not just a circuit
board. I would not spray on the components (put a bit of painter's
tape on them). They may need air circulation for cooling. If nothing
like that is available, use WD-40 and a toothbrush. That should also
help keep the moisture problem at bay.
__ __
Randy & \ \/ /alerie's
\__/olvos
'90 245 Estate - '93 965 Estate
"Shelby" & "Kate"
 
Reply With Quote
 
Jon Robertson
Guest
Posts: n/a
 
      20-10-2009
I have seen a GM car with zinc blocks attached to the body to act as
sacrificial anodes I am interested in what Mr Sweet or Mr Klien think of
this seriously /
"James Sweet" <(E-Mail Removed)> wrote in message
news:hah14d$sp2$(E-Mail Removed)-september.org...
> Boris Mohar wrote:
>> From 2005 XC90 CEM A Volvo mechanic showed me this bit of insanity. The
>> CEM1 circuit board
>> sits on top of CEM3 circuit board and they are soldered to each other
>> via
>> header pins. CEM3 is conformably coated but CEM1 is not. The difference
>> due
>> to exposure to elements is obvious. What possessed Volvo to protect one
>> board and not the other?
>>
>> http://www.viatrack.ca/Misc/CEM1.JPG
>> http://www.viatrack.ca/Misc/CEM3.JPG
>>

>
>
> That is strange.
>
> The corroded one looks repairable though, I've fixed pinball machine CPU
> boards that were in much worse shape from the memory backup battery
> leaking all over them. Vinegar wash followed by a careful scrub with a
> brass bristled brush can work wonders.



 
Reply With Quote
 
James Sweet
Guest
Posts: n/a
 
      21-10-2009
Jon Robertson wrote:
> I have seen a GM car with zinc blocks attached to the body to act as
> sacrificial anodes I am interested in what Mr Sweet or Mr Klien think of
> this seriously /



Well it ought to reduce body corrosion, but I seriously doubt it would
have any effect on the inside of electronics. There exist potential
differences due to power supplied to the circuit and whatever is more
positive will be the anode either way.

Zinc is often used on boats, and works well to prevent corrosion of
metal hardware.
 
Reply With Quote
 
Junior Member
Join Date: Nov 2010
Posts: 1
 
      28-11-2010
Thinking of replacing a CEM myself... possible, as a home garage mechanic?
Does it need a software update to go with it?
 
Reply With Quote
 
Junior Member
Join Date: Sep 2011
Posts: 1
 
      25-09-2011
I have a 2003 XC90 T5 AWD (right hand drive).

My CEM is playing up - classic symptoms of cutting out whilst driving (seems to only occur on long trips when its warmer. Stopping for half an hour seems to fix it).

So looking at DIY replacement, or at least ordering some parts on line and taking to my dealer.

Where is the CEM located, and how does the water get in?

Where to buy on-line? swedishautoparts dot com?

Thanks
Hamish
 
Reply With Quote
 
 
 
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
CEM-codes Volvo S80 2.9L Volvo S80 6 29-03-2006 06:23 AM
Removing the CEM Civster General Motoring 3 20-03-2006 02:41 AM
V40 CEM Module, whats it for???? lee.jones@comtech55.freeserve.co.uk Volvo V40 1 08-02-2006 02:18 PM
Corrosion Warranty (UK) can somebody give me the rundown... LaoFuZhi General Motoring 3 07-07-2004 10:18 AM
V40 Corrosion Advice (UK) LaoFuZhi Volvo V40 2 01-07-2004 12:10 PM


All times are GMT. The time now is 12:31 AM.