SwedeSpeed - Volvo Performance Forum banner

1 - 2 of 2 Posts

6 Posts
Discussion Starter · #1 ·

First of all I know, that the message "Anti-Skid service requried" is a real collection of many-many possibly failing sensors, modules, wirings, etc... But, the problem exists already a time ago and I have stopped by some dealerships, and by some "experts" to find out, what the root cause is.

So, the symptoms are:

-"Anti-Skid service requried" warning message, of course (at the beginning it just showed up after 20, or maybe 30 mins of driving in normal conditions, then I shut down the car, restarted, it disappeared, then approx. after 2-3 weeks after the first encounter with this message it came on already on startup...)

-AWD - it's clearly not working, I have lifted the car, startup, first gear: front wheels are spinning, rears don't. If I'm right, Haldex sends at least 5-10 % to the rears on standard.

The first visit at a dealership service:

-After two hours of work they could only say, that the steering angle sensor is okay (when they saw the "Anti-Skid service requried" message, they were about 100 % convinced, that the SAS is the failing component). After I went back to collect my keys from the dealership and pay literally for nothing helpful, they said, that MAYBE the changing of the DEM and/or the AOC pump should solve the problem... Sorry? The DEM itselfs costs about 2100 EUR, the pump another 400 EUR. Yeah, if they could say with 100 % confidience, that this are the failing parts, then okay, but... spend 2500 EUR's to MAYBE solve the problem, it doesn't sounds a deal for me.

My first try to determinite the root cause:

-I have tried the Xemodex flow chart, the AOC pump works fine, but I'm planning to replace it anyway, just to be sure. The fuses, the REM is also okay.

-I have changed the oil in the Haldex and the filter itself. I have bought the car with 114k km's and I'm afraid that the previous owners didn't paid that much attention to the Haldex and the rear differential.

The second visit at (an another) dealership service:

-I have here at least recieved a report with my diagnostic trouble codes. Fault codes in relation with the Anti-Skid system:

-BCM-0094: Communication between control units Communication problem with DEM, but! DTC is found not active!
-CEM-1A64: Communication with AOC control module Signal missing, but! DTC is found not active!
-DEM-000B: Oilpressure Faulty value, and DTC is found active!
-SAS is OK.

For me, this means that the oilpressure sensor inside the Haldex unit is NOK. I think a replacement (in pair with the AOC pump, of course) should solve my misery, or what do you guys think? Because the other trouble codes, regarding faulty/no communication between the control units such as BCM-0094 and CEM-1A64 they are found not active...

So I tought I will replace the pressure sensor and then clean the DTC history. I think it has a higher chance that due the lack of maintanance of the Haldex unit the oil pressure sensor is damaged and therfore the DEM could not send information to the other control units, than that the communication routes between the DEM-BCM and DEM-CEM are paralel failing.

The Haldex "expert"

-Nothing... He has spent 5 hours investigating the car (I was not there, so I cannot provide further information about his methods) hecould only say, that there is a CAN-Bus communication error, and he should check the wiring. After 5 hours... He is now on search for a wiring diagram, I guess he won't show up anymore.

So, what do you mean?

Thanks for your help. Regards, Péter from Hungary

1,080 Posts
So the BCM and CEM codes were "found not active"? Meaning they were previously stored codes? Are they saying that the DEM oil pressure code was the only active one? If that's the case then it likely means that you have a faulty AOC unit pressure sensor. It is plugged into the DEM and which mounts to the AOC unit. That would be my first guess, assuming that you have no other codes and those were ALL of the codes they found.

If you have VIDA, I would clear the codes do some driving for a couple of days, then read the codes again. If the DEM code is the only one that comes back, then I would say that it is indeed your pressure sensor that is at fault.
1 - 2 of 2 Posts