hi everyone.
My 2014 XC70 D5 AWD and I are new to the forum.

When I drive below 30 mph on a smooth road there is a droning noise coming from the drivetrain. It increases and decreases with the speed of the car but does not seem to be related to the wheel speed. I have just fitted new Pirelli Scorpions. About 2 weeks ago I got the dreaded rear transmission service warning, I got the code read and it related to the Haldex system. I cleared the code and it has not recurred. There are no other error code so showing.

Thoughts?

51,000 miles. Does not seem a lot to need gearbox or differential oil changes. I've never used it for towing. Thanks will talk to my local independent