CEM clean now PS (EPS) pump on all the time

[supafly]

Hi,

Thanks for your suggestion. I took the CEM out and cleaned all the connectors then plugged it back in again. It was the first thing I tried, after this the power steering pump started to continuously run.

There's something wrong with the PS circuit or the canbus system? I'm stuck now as to what else to check.

[supafly]

Just got home and noticed that the red alarm led is not flashing anymore when locked.

Power steering service required error is still on the dash but everything else seems to be working fine.

Does anyone have any other suggestions on how to diagnose further?

[supafly]

Just had the full Christmas light experience after working out that the alarm wasn't working. Brake failure, srs error, radio buttons inoperative, dashboard display turning off...

Patience is definitely being tested now.

Is there a way to test the cem and the ecu?

Can this be done through Vida dice with the errors I'm getting as I think it may also affect communications?

[IainG]

Hi
Have you checked your alternator?

Iain

[supafly]

Thank you for your help.

I haven't checked the alternator yet as it was replaced just under a year ago, probably only done a thousand miles since then.

What/how do I check? I understand that these are 'smart' alternators and can vary output on request?

One thing I forgot to mention was that there is no power steering now too.

[supafly]

IainG, you got me thinking... when I took the battery out to charge while I worked on the car (less than a year old exide).

I did see that the short side that faces the front of the car was slightly swollen. Initially I thought it was due to a lack of cooling as the battery cover is broken at the point it passes under the strut brace.

Now that you have mentioned the alternator it could be due to overcharging..?

I can check for voltage at idle, 2000 rpm and if there is any ac voltage, but do you know what other checks I can perform?

[IainG]

Hi
The only reason I mentioned the alternator is that I had the "Christmas tree lights" up a couple of times before imy alternator failed on my V50. Has happened twice in 10 years.
I know the electronic modules are very fussy over their voltages. Not sure of any more specific tests, more than you suggest. I have a vague recollection of someone else posting how to test the alternator but can't remember specifics. Google search of the forum might bring it up
Think there are also some charging tests in Vida using a Dice. It tests the voltages at the different temperatures
Iain

[supafly]

Thank you for your reply. I'll search the site during my lunch break today to see if I can find it.

I did manage to find brand new denso alternators for under £120 last night, I was surprised at how cheap they are considering refurbished units are more than half that.

[supafly]

I also found this potential cause while searching...

From... https://forums.swedespeed.com/showth...ard-it-before-!

by - Ruan

"It's the connections to the CEM - the left hand plug on top of the module (small one) is the one that seems to cause the fault, on RHD cars anyway there's a bit of plastic right next to the connector which appears to rub on it and cause it to wear out the connector on the CEM board which in turn allows the plug to pop up - once this happens, you cannot see it, but the connector is partially disconnected, which then causes the spurious issues.

I've had this happen 3 times since and every time ripping down the CEM board and re-plugging this connector instantly solves the issue.

For anyone who has this issue - try that connector.

The reason Volvo invariably say that the CEM has failed is that they cannot actually see that the plug is partially disconnected, of course, they replug it and it'll last another few weeks/months until same thing happens again. The more the soft plastic of the CEM wears, the more often the problem will happen - next time I have this apart I will try and take photos, the actual plastic on the CEM now is really quite worn on mine, you can see where it's vibrated and caused it to not hold the connector in correctly. Had another friend with a V50 D5 who had precisely the same issue, told him to check that connector and his was solved by that connector, he ended up replacing the CEM as the plastic was so worn the connector wouldn't attempt to stay in, soon as the module was clipped back in, the piece of plastic that touches the connector instantly just caused it to unplug!"

[supafly]

Also for completeness and to keep things together in one thread, I found this...

from https://www.volvoforums.org.uk/archi.../t-152548.html

by - Clan

"remove the air filter assy , check the whole engine bay loom everywhere for rubbing around the gearbox area AND on the sharp AC Pipe crimps behind the right hand headlamp , also in the same area the loom runs over the sharp chassis edge .
if you push and pull the loom to move it , even if te CAN network is earthing out , the fact you have moved it could well cure it for the rest of the cars life"

In my case I did this but couldn't find any issues apart from near the OSF as the loom came around past a part of the strut housing it was tight. So I added a piece of fuel hose between it even though the wiring showed no signs of damage there.