s320 (w220) power trunk

[Eastern]

Hello

I have a problem with a s320 power trunk , the trunk will open and close as it should but when it closes some times it closes you will hear it lock but on the right side near the window it will raise the trunk.

what i found out is that most likely the hydraulic unit is pushing to long and therefor lifting the trunk.
when you open and close it again ( 1 or 2 times )it will not lift the the trunk

the hydaulic unit is working and most of the times is will close normal what i found on the internet is that there are 2 relais that might cause the problem or a potentiometer that is in the system and tells how far the trunk is open or closed.

is ther anybody here who nows this problem and can tell me how to fix it ?

thanks
ron

 

[Eastern]

Nobody has any ideas , I suspect this is not the first time for this problem.
When I find a solution I will post it , but i think it will be a dealer visit.