[cosmo325xi]

Hello Everyone. I have a 2006 BMW 325xi and I have had the trifecta on for a while and the car has been driving fine in RWD. The lights normally pop on as soon as i start driving. The past couple days when I start driving the car instead of the trifecta coming right on, the car makes this scraping nose from the rear and barely moves. It almost sounds like the rear brake is locked up. Once the trifecta comes on and the car is in RWD it drives fine but I hear a clicking noise coming from the rear.

I figured it could be the transfer case actuator as those often go bad but I was thinking the wheel speed sensor could have been culprit the whole time. If the sensor doesn’t work I am debating replacing the actuator motor. (The sensor is easier to do so i did this first just in case lol)

Not sure the best way to diagnose, I put the new wheel speed sensor on tonight and am going to try to drive it tomorrow. I replaced the radiator and power steering reservoir so I need to put new fluid in before driving it. Any insight can help as most people don’t have this clicking and scraping noise issue on the forums.