Engine system service required after service 2008 XC90 D5

[ChrisY73]

Hi my D5 185 has just had a full service at 120,000 with my local garage and after approx 30 miles the engine system service required message appeared. We have cleared the message but it keeps coming back after a few days. I should probably take it to specialist but before I start throwing money at it thought I should seek advice here.
It drives fine but looking at the dipstick I think he may have overfilled the oil, which corresponds with other people online. Is it worth initially trying to drain out some oil and clearing the code first?
I’ve used the garage for years and trust him but he could have made a mistake here...

[gmonag]

Yes drain some oil out (only 1 litre or so). The level should be at the 1/2 mark.

[4x4]

Difficult to drain 1 litre out without making a bit of a mess, better to use an oil extraction pump and remove the excess that way. Oil requires to be hot for easy extraction using these type of pumps

[gmonag]

or drain the sump into a clean container, and pour most of it back in the engine.

[colinbos]

Only go to 2/3rds of the dipstick MAX.

If you have VIDA to read the amount, 70% is the optimum volume of oil in the engine.