Rear Diff change (4 wheel drive service required)
 

2010 Volvo XC70 D5 Manual. Bought this car with really loud rear differential whine. I bought a 2nd hand diff with the same part number and got my local garage to change it for me. New diff is quiet but is throwing up a 4 wheel drive not functioning service required code. Do I need to do some sort of reset through Vida or is the Haldex pump on this diff knackered. Before the garage changed them over I did a service on the Haldex (new filter & oil) which went smoothly.

When you had the diff swapped did this include the DEM. If so be worth putting your original one back on but ideally Vida would show you where the fault lies. I’m just thinking the car may not recognise the new diffs DEM if it was fitted as an entire unit.

Didn’t think of that
 

Just read up on the DEM, didn’t know about this little box of electronics & changing it with the original makes perfect sense. Luckily I kept the original Diff for when this 2nd hand one gets noisy to have it reconditioned so I’ll swap it over. Looks straightforward enough. Thanks 🙏