2013 XC90 CEM ABS Woes

jkorpi · Post by **jkorpi** » 09 Feb 2022, 08:00

I've got a 2013 Volvo XC90. Currently the Brake, ABS, Anti-Skid lights are on, the odometer is not functioning, and the trip meter goes to "-----" after about 10 seconds of turning the key on. There have been intermittent bizarre electrical quirks such as the brake light turning on in the middle of the night when the car is off, the key sometimes works to unlock/lock the doors, but often does not.
I've brought the car to a Volvo dealership and they said that in order to fix the brake, ABS, anti-skid issue they would need to replace the BCM. I replaced the BCM and nothing was solved. I brought the car to another dealership and they said that the CEM needed to be replaced. As you know, every time you bring a Volvo to a dealership it is a standard $2000 fix-whatever fee. I took out the CEM to see if there were any signs of the notorious moisture leaks through the plastic covering under the windshield wipers. The CEM looks brand new aside from a bit of dust on the exterior case. Inside the case, the CEM looks gorgeous. Not a sign of anything awry. I made sure to clean the board and contacts with electrical cleaner and gave the connections a slight coat of silicone dielectric compound to ensure conductivity and corrosion protection. I put it all back together and nothing changed. Lights are still on. The car runs fine. I followed Xemodex's flow-chart for testing the ABS...CEM and found no power going to the fuse #15. As you can imagine, I am hesitant to take this car to anyone else, because I'm getting all sorts of different opinions even from the dealerships with VICE...
So... I am worried that whatever I do with the CEM it will not fix the current issues and I am back at the beginning. These Volvo electrical problems are stunning given the price of these vehicles.
Any thoughts on what to do next?

Post by **xHeart** » 09 Feb 2022, 12:57

jkorpi wrote: ↑09 Feb 2022, 08:00 I've got a 2013 Volvo XC90. Currently the Brake, ABS, Anti-Skid lights are on, the odometer is not functioning, and the trip meter goes to "-----" after about 10 seconds of turning the key on. There have been intermittent bizarre electrical quirks such as the brake light turning on in the middle of the night when the car is off, the key sometimes works to unlock/lock the doors, but often does not.
I've brought the car to a Volvo dealership and they said that in order to fix the brake, ABS, anti-skid issue they would need to replace the BCM. I replaced the BCM and nothing was solved. I brought the car to another dealership and they said that the CEM needed to be replaced. As you know, every time you bring a Volvo to a dealership it is a standard $2000 fix-whatever fee. I took out the CEM to see if there were any signs of the notorious moisture leaks through the plastic covering under the windshield wipers. The CEM looks brand new aside from a bit of dust on the exterior case. Inside the case, the CEM looks gorgeous. Not a sign of anything awry. I made sure to clean the board and contacts with electrical cleaner and gave the connections a slight coat of silicone dielectric compound to ensure conductivity and corrosion protection. I put it all back together and nothing changed. Lights are still on. The car runs fine. I followed Xemodex's flow-chart for testing the ABS...CEM and found no power going to the fuse #15. As you can imagine, I am hesitant to take this car to anyone else, because I'm getting all sorts of different opinions even from the dealerships with VICE...
So... I am worried that whatever I do with the CEM it will not fix the current issues and I am back at the beginning. These Volvo electrical problems are stunning given the price of these vehicles.
Any thoughts on what to do next?

How old is battery; a Volvo original?

Post by **vtl** » 10 Feb 2022, 05:27

Did you read the codes?

jkorpi · Post by **jkorpi** » 11 Feb 2022, 06:11

Thanks for the questions. I'm not sure about the battery...it was my father-in-law's vehicle before we got it. I have not changed it. Would this throw things off this much? With a multimeter it reads somewhere around 12.4 V.
Also, the codes were read by both Volvo dealerships, each coming up with their own thoughts on what was wrong (i.e. first thought it was the BCM and now the second thinks it is the CEM).
The folks at Xemodex said there is a typical fault with these CEMs which cause them to not send power to fuse #15, which is the fuse for the BCM. Given that my CEM looks gorgeous, I'm wondering what this fault could be. Relay? Transistor? I looked at all the soldering points and they looked great.

Post by **vtl** » 11 Feb 2022, 06:29

My 05 XC70 got a broken wire in one of two CEM relays:

Of course, part is $1600, plus 2 hours of labor and CEM reflash, totaling in about the same price tag the whole car is worth on the market. Oh, wait! The relay itself is cheap, the customer can solder a new one...

chitownV · Post by **chitownV** » 11 Feb 2022, 13:43

I am not sure how a CEM can look gorgeous vs just in working order, lol. But, Xemodex is usually pretty good about helping trouble shoot from what I have heard and seen on the interwebs. Can't vouch for them as I haven't needed to use them, but if I came up with the same situation, I would go to them.

That said, providing power to fuse 15 for the BCM, well that could certainly be a naked-to-the-eye issue, especially on circuit boards. It might be worth it to send it to Xemodex and if they find it is still good after they have tested it, then ask them if you don't have to pay for the repair fee. The true cost is downtime and shipping.

If the vehicle is already down, then see if they can check the BCM too at the same time. Non-Volvo, I have worked with brake control modules as the source of traction/ABS/Brake issues. They call it the tree of lights and with all of the brake associated lights showing, it is almost always the BCM. However, Xemodex would know better for the Volvo.

Good luck!