Finally got the trunk assist working..partially
Thread Starter
Senior Member
Joined: Mar 2019
Posts: 269
Likes: 93
From: Las Vegas, NV
2003 S55 AMG, 2005 C320 Coupe, 2020 Jeep Gladiator Mojave
Finally got the trunk assist working..partially
Since I've owned this car the trunk assist has never worked and I knew the hydraulic pump had a damaged reservoir (It was also unplugged, so the PO knew about it!). I bought a used/refurbished one from eBay about 6 months ago and finally got around to installing it yesterday. I don't have any PSE leaks, soft close works on all doors and trunk lift supports were changed shortly after I bought the car because they were shot. Prior to installing the new pump I dumped the trans fluid that was in it, cleaned it and refilled it with Pentosin CHF (to the correct level) since I had some left from my ABC flush.
I have not touched anything except installing the 2 lines (yes the red and blue are in the correct locations) and plugging in the electrical connector. It goes open with the door switch and key fob, but not closed. It will still close manually with a little more resistance, as expected. I hear the hydraulic pump make an attempt to close but it stops. I've dug through numerous threads on trunk assist issues and I'll try the reset with the door switch before I move on.
Feel free to chime in if you have any input. I'll report back when/if I resolve it.
I have not touched anything except installing the 2 lines (yes the red and blue are in the correct locations) and plugging in the electrical connector. It goes open with the door switch and key fob, but not closed. It will still close manually with a little more resistance, as expected. I hear the hydraulic pump make an attempt to close but it stops. I've dug through numerous threads on trunk assist issues and I'll try the reset with the door switch before I move on.
Feel free to chime in if you have any input. I'll report back when/if I resolve it.
Member
Joined: Jan 2019
Posts: 146
Likes: 61
From: Panama City, FL
2007 Jaguar XJ8L, 1999 Miata, 2003 Yamaha FJR1300
My car was towed away a couple of years ago after being flooded so I may be talking out my butt, but I don't remember the trunk lid closing from the remote, only from the button on the lip of the lid, a separate close button.
Thread Starter
Senior Member
Joined: Mar 2019
Posts: 269
Likes: 93
From: Las Vegas, NV
2003 S55 AMG, 2005 C320 Coupe, 2020 Jeep Gladiator Mojave
I read up on the operation of the system and I believe you're correct, the door switch (RTL) and red button on the trunk lid for closing. I did perform the reset and it opens and closes with some slight assistance so it's not quite 100% just yet. I'll dig into it more when I have time. It's never worked since I've owned it so I'll chalk it up as progress for now.
Senior Member
Joined: Oct 2011
Posts: 320
Likes: 185
From: Philadelphia
2002 CLK55 AMG: 2004 S55 AMG: 2009 C63
Curious about this as well.
When i received my car, the trunk assist did not work. I was able to get it working and i installed 2 new trunk shocks as well. If the trunk is closed, i can gently press the button under the trunk and it will pop. But in order for me to get it to open, i need to pull up on the trunk slightly while also pressing the button until it actuates and opens by itself. If it pops and i press the button once again to open, it won't do anything. Almost as if it is not sensing that the trunk is popped until i lift up on it to get it going.
Closing it i need to start the process for it as well as the pump is weak/low on fluid. I need to pull it out, flush the system and put some fresh fluid in as well, and i think that may work. Would love to get the whole system operating the way it should as it is a nice feature
When i received my car, the trunk assist did not work. I was able to get it working and i installed 2 new trunk shocks as well. If the trunk is closed, i can gently press the button under the trunk and it will pop. But in order for me to get it to open, i need to pull up on the trunk slightly while also pressing the button until it actuates and opens by itself. If it pops and i press the button once again to open, it won't do anything. Almost as if it is not sensing that the trunk is popped until i lift up on it to get it going.
Closing it i need to start the process for it as well as the pump is weak/low on fluid. I need to pull it out, flush the system and put some fresh fluid in as well, and i think that may work. Would love to get the whole system operating the way it should as it is a nice feature
Thread Starter
Senior Member
Joined: Mar 2019
Posts: 269
Likes: 93
From: Las Vegas, NV
2003 S55 AMG, 2005 C320 Coupe, 2020 Jeep Gladiator Mojave
Replacing trunk shocks was the first thing I did, they were shot. I'm also wondering if the trunk hydraulic pump fluid is low on mine. I do the same thing, after a tiny nudge it goes. On its own, it won't move. I'll mess with it when I have time see what I figure it out.
