Well, I've opened the cluster once again, since I'm getting faulty messages telling me the oil is low, and the gas is empty when there's still well over 20 liters (25%), and since I've been meaning to do it for a long time, it's time to replace the capacitors.

They are :
1000µF 16V
220µF 16V
4.7µF 63V
(63V?? An odd number in my book, all puns aside)

Next step: reassemble the cluster again, put it back in the car, drive to go get the capacitors Saturday (the specialty store closes too early for me to get there in time during the week).