I have a 2005 Volvo xc90 2.5t with 110k
I've looked everywhere and can't seem to find any answers to my issue. I'm hoping if I explain it below I can get some information.
The ABS / Anti Skid Brake assist message started appearing on my dash. I was told it was the controller unit, took it out of the car, and sent it out to be rebuilt, and reinstalled it and the light went out for months. All of the sudden, the light is back on. I assume it is probably the controller again.
The next issue that I have determined is related to this ABS controller is my transmission shifting. We all know Volvos can have the shift flare ups etc. Well, when the ABS controller is connected to my vehichle, wheter the ABS ANTI SKID BRAKE ASSIST failure is lit or NOT lit, the transmission has weird shift points and flare ups. When this controller is connected, the shift from 2nd gear to 3rd gear seemed to be flared, with another shift in there that didn't feel right. For instance, if I shifted it in manual mode, from 2nd gear to 3rd gear I'd get another shift, even when I was not shifting it. Just strange. In short, even after I had the controller for the ABS rebuilt the tranny still acted up doing the same things.
Now, I have removed the controller altogether. My transmission shifts perfect. No weird shifts. No flare-ups. Manual mode works great. Of course, I now have no ABS and probably no traction control. And my dash looks like it's Christmas with all the warning lights.
What could be causing this? It all seems to be related to the ABS controller. Do I need to bite the bullet and spend over 1k for a brand new one from Volvo? I'm just really trying to understand the issue here.
I've also had Volvo reset the driver adaptive on my tranny after the ABS controller was rebuilt. That did absolutely nothing and as long as that controller was plugged in, the trans still continued to have flareups and odd shifts.
Any input here would be appreciated. Thanks!






