Replace Yamaha ebike side-switch display A - question

[BikerBobbyGreen]

My Yamaha side-switch display unit type A is defective. I plan to replace it. Is the odo & trip mileage data stored in the side switch unit itself or is it stored in a memory in the motor unit in the frame. Or, to put it another way, do I lose the mileage data when I put the new unit in or does the new unit upload the old data from elsewhere in the bike's electrics? It's a Haibike hardtail 6. Many thanks for any help.