How do you determine if the trunk hydraulic pump needs to be replaced?
03-20-2019, 04:47 PM
#1
How do you determine if the trunk hydraulic pump needs to be replaced?
Hello all,
I have a 2005 S430. My trunk does not lift or close on its own. The actuator works because it unlocks but I would have to manually lift the trunk and close myself. It is not the struts because I purchased new ones and the trunk stays up when lifted. The hydraulic pump next to the battery is still currently full of fluid. Pressing any of the open and close buttons from the vehicle or fob has done nothing and cannot hear any noise from the hydraulic pump to indicate that it is working or trying to work. I have checked the 20a fuse under the rear passenger seat and is still functional. I have a 12v light tester but don't know where to point it at the hydraulic pump to test for power going into the pump. Does it sound like I need to purchase another hydraulic pump? Any help would be greatly appreciated. Thank you.
I have a 2005 S430. My trunk does not lift or close on its own. The actuator works because it unlocks but I would have to manually lift the trunk and close myself. It is not the struts because I purchased new ones and the trunk stays up when lifted. The hydraulic pump next to the battery is still currently full of fluid. Pressing any of the open and close buttons from the vehicle or fob has done nothing and cannot hear any noise from the hydraulic pump to indicate that it is working or trying to work. I have checked the 20a fuse under the rear passenger seat and is still functional. I have a 12v light tester but don't know where to point it at the hydraulic pump to test for power going into the pump. Does it sound like I need to purchase another hydraulic pump? Any help would be greatly appreciated. Thank you.
03-21-2019, 02:22 PM
#2
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2009 E350 4M Avantgarde;mistress 2002 S600; wife 2014 C300 4M
It's a complex system, and don't throw any parts at it without knowing exactly what you are doing!
The yellow 20A fuse has nothing to do with it, it's for the PSE system.
There are switches on the trunk lock actuator, a position sensor on the hydraulic actuator, a switchover relay and other things involved.
Among other tasks it may require a reset with an SDS system, because it may have been locked out due to a detected fault.
At 15 years old, it may be cheaper just to manually lift it up, as you say it does unlock.
Good luck!
The yellow 20A fuse has nothing to do with it, it's for the PSE system.
There are switches on the trunk lock actuator, a position sensor on the hydraulic actuator, a switchover relay and other things involved.
Among other tasks it may require a reset with an SDS system, because it may have been locked out due to a detected fault.
At 15 years old, it may be cheaper just to manually lift it up, as you say it does unlock.
Good luck!
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izmirli (08-17-2020)
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