Wife wants her back up sensors back. The AWD seemed to fail at about the same time.


I have a series of codes I was hoping someone could lead me in the right direction to troubleshoot. These all seem related


From VIDA reader
Brake Control Module U011400 Lost Communication with DEM
CEM: 1A64 Communication with AOC Control Module missing
REM: DD10 Lin Communication Communication fault


This is on a 2006 XC90 V8

 

Hi.
I have the same messages as you have typed.
Did you find out the cause and how to fix it?
thanks in advance.
Mark.

 

 

Gents, any progress or a solution to this issue?

Have the same problem with my XC90 D5 -13. Back up sensor and anti-spinn (DSTC) stopped working roughly at the same time. Might have been related to a drive in heavy rain.
First intermittent, now permanently. Removed the DEM and checked both connectors, both looked good. However, a corner of the rubber gasket btw the pressure plate? and the DEM had a leak and there was a bit of oxide build up on the outside of the plate, but not inside of the DEM where the electronics sit.

Any advice would be appreciated - or any insights in how to test or verify the functionality of the DEM unit, before I ship it of for repair...

Thanks

 

Test flowcharts are found under the blog tab then resources on their website


https://xemodex.com/us/dem-diagnosti...c60-xc70-xc90/

 

Brilliant - thanks!

So, using their flow chart for troubleshooting the DEM I found that I don't have 12V on fuse #23 (or any other fuse in that small group) on the REM module that feeds the DEM.
The larger fuses on the REM all have 12V
My scan tool tells me there is no link to the DEM, nor to the REM.
So my conclusion is that the REM module is shot and thats where I should start. Obviously I dont know anything about the status of the DEM yet since its not getting power, and I havent tried feeding 12V directly to it.

I have previously had a similar problem with the CEM module, a group of fuses were not getting any 12V feed and that time it was a faulty relay inside the CEM that needed to be replaced. I havent looked inside the REM module yet but I hope it has a similar layout with a relay controlling that group of fuses.

 

Do you have this info? The 30a fuse #27 powers that row of fuses (20-26)

 

Yeah, thanks. I figured that out from the fuse overview in the user manual. I think I had 12v over it but notnsure if i remember correctly. Now the REM is out of the car but at least fuse #27 is not broken.

I'm Swedish, we've had Volvos since I was a kid, i was probably even made in an Amazon. I love Volvos for their mechanical solidity. But the quality of the electrical system... not so sure

 

Alright gents, I think I've located the problem.

I opened up the REM module and found 2 identical relays on the board, named V23134 J52 X455. They have an internal resistor btw leg 85 and 86 of 470 Ohm. The resistance of the internal coil should be about 74 Ohm. When I measure the resistance on the one circled in red, I get 470 ohm. The other one shows 74. That tells me that the coil in the circled relay is burnt. Luckily I had some spare relays lying around since I repaired the CEM. They are called FRC3A-1A and have the same specs as the originals - except there is no resistor btw leg 85 and 86. So, I will now solder a resistor on the new relay, remove the burnt relay from the board and replace it with the new one and put everything back in the car and see if I get 12v over the fuses. I hope this resolves the issue, but the fact that there was no link btw the units makes me worried. Well, we'll see what happens.

If this is the wrong place to post this, since the original post is quite old, please let me know.

 

Problem solved!

Removed the broken relay and replaced it with the 10 EUR relay with the added resistor of 470 Ohm, put the REM box back together, installed it back in the car, hooked up the battery and turned on the ignition. The anti skid service and back up sensor service messages were gone and everything works just fine. I'm happy again and saved the cost of having the REM module replaced at a garage,

 

Thanks for posting this.

 

Finally got round to fixing this problem, as per Böllster's suggestion. Just adding a few details for those, like me, less experienced in repairing cars.
For context, my local Volvo dealer quoted 2500€ to replace anti-skid module, REM and back-up sensors.
The actual problem is just a 15€ relay.

Ordering the relay
In Europe, you can order the exact relay from mouser.fr, product number (592-)1-1414610-0 which gets you the V23134J0052X455.
https://www.mouser.fr/ProductDetail/...UX3L2j7w%3D%3D
They have detailed product specs on their website.

Removing REM
I couldn't find any post detailing how to unmount the actual REM module in the trunk. It turns out you do need to remove a lot of interior panels, starting with the light in the roof panel and then gently working your way down in the left side. There are a couple of bolts (4) to undo to remove the main panel. All connectors from the REM are easily removed, and then you can unclipse it. I disconnected the battery before touching the REM.

Repairing REM
It's a bit of a struggle to open the plastic box of the REM. You do need to unplug all the visible fuses first. The inside is, obviously, a rather delicate printed circuit. Being inexperienced, it took me about an hour to actually remove the relay from the board with a soldering iron, heating each peg one-by-one whilst at the same time exerting a continuous pressure on the relay. I removed excess tin with a sucking device before plugging in the new relay. Closed the box and put back all the fuses.

Mounting REM
Basically followed steps in reverse order to get the car back in original state, and lo and behold - the warning messages had disappeared and my park assist works again!


This is what your car needs to look like to dismount the REM. Start with the dangling roof lighting, then work your way down.


You'll need to unplug all fuses to open the plastic casing of the REM.


The culprit (shown here without casing).


After a long battle, finally managed to remove the relay. Note I damaged the circuit board slightly.


New relay soldered.


No more error messages - mission accomplished.