Ok I did another test with the service menu in access 4. Maybe I did it wrong last time but well here it is :

A4.11 : stays at 1 when being down and jump to 0 when raising a bit then back to 1 when down

A4.12 : stays at 1 and change to 0 when I'm almost at the highest height then goes back to 1 when lowering and down

44.13 : seems to stays at 1

Also, sometimes when the code 253 appears I can't raise can move forward very slowly. If I keep it full forward then sometimes the code 253 disappears and the wave is back to normal

So... more like a height switches problem? I'm thinking of just replacing the 3 switches at once...