R350 lifgate latch/lock not working, draining batter..fixes, adjustments & part #'s
Thread Starter
Senior Member
Joined: Jul 2009
Posts: 392
Likes: 21
From: Northern Suburb of Indianapolis
CLS55
R350 lifgate latch/lock not working, draining batter..fixes, adjustments & part #'s
All,
First I'll start with my question...what do they do when they 'adjust' our latch? I see reference to this all over. Anyone know exactly what is being done there? I'd like to try that before buying new parts.
My tailgate opens and closes automatically so that works, but it no longer latches/locks (it looks shut but I can still pull up on it). We also get a message on dash telling us it is open.
I believe it is also draining my battery as I can charge my battery overnight, then hours after I unplug the charger I'll come back to the car to hear a constant beeping sound. Neither the dash display nor the dome lights worked....putting key in did nothing. All I could do was hit the reset button (labels 'R' on dash) to turn off constant beeping. Voltage of the battery when tested was extremely low.
At any rate, I pulled of all the interior trim from the tailgate. It took about 45 minutes as I was being very careful not to break the yellow or metal tabs that attach the trim to tailgate. Some people just buy new yellow tabs (what are those called...?) but since I did it carefully I didn't break any. Tips...the external button to lift the gate...behind it is a plug, as you pop off that side be sure to pull the plug off so you don't break anything (it doesn't pull right out, you have to use a very small screw driver to lift a flap of plastic up to in essence 'unlock' the plug and pull it out). Beyond that just go slow and be careful...don't be afraid to exert a little force (quick pops) to dislodge certain areas. Some trim at the top of the window does have a start headed screws in them so don't pop/pull everything off.
All that said I just want folks to know this is not hard. Don't pay MB $200-300 to take this off and put it back on for you.
I also bought a new battery and replaced that today (mine just didn't have a lot of cranking amps any longer...another job I see people paying for...also quite easy though you'll want some upper body strength to lift battery out without dropping it on the fuse box that site next to it). I then unplugged the harness plug that leads to the latch/lock. So far its been a few hours and the battery is holding voltage.
So I'd like to see just what is 'adjusted' at the dealer and try that. I'm also going to try what someone else suggested to turn off the tailgate lift limiter that keeps it from going up to high (I guess just turning this setting off at the dash fixed their issue). If all else fails I'll just replace the latch/lock mechanism. it looks very easy to pull out and get back on. I found the part for $200 +30 shipping on parts.com
Any input is welcome. I'll be sure to update as I get more into this for others' future reference.
First I'll start with my question...what do they do when they 'adjust' our latch? I see reference to this all over. Anyone know exactly what is being done there? I'd like to try that before buying new parts.
My tailgate opens and closes automatically so that works, but it no longer latches/locks (it looks shut but I can still pull up on it). We also get a message on dash telling us it is open.
I believe it is also draining my battery as I can charge my battery overnight, then hours after I unplug the charger I'll come back to the car to hear a constant beeping sound. Neither the dash display nor the dome lights worked....putting key in did nothing. All I could do was hit the reset button (labels 'R' on dash) to turn off constant beeping. Voltage of the battery when tested was extremely low.
At any rate, I pulled of all the interior trim from the tailgate. It took about 45 minutes as I was being very careful not to break the yellow or metal tabs that attach the trim to tailgate. Some people just buy new yellow tabs (what are those called...?) but since I did it carefully I didn't break any. Tips...the external button to lift the gate...behind it is a plug, as you pop off that side be sure to pull the plug off so you don't break anything (it doesn't pull right out, you have to use a very small screw driver to lift a flap of plastic up to in essence 'unlock' the plug and pull it out). Beyond that just go slow and be careful...don't be afraid to exert a little force (quick pops) to dislodge certain areas. Some trim at the top of the window does have a start headed screws in them so don't pop/pull everything off.
All that said I just want folks to know this is not hard. Don't pay MB $200-300 to take this off and put it back on for you.
I also bought a new battery and replaced that today (mine just didn't have a lot of cranking amps any longer...another job I see people paying for...also quite easy though you'll want some upper body strength to lift battery out without dropping it on the fuse box that site next to it). I then unplugged the harness plug that leads to the latch/lock. So far its been a few hours and the battery is holding voltage.
So I'd like to see just what is 'adjusted' at the dealer and try that. I'm also going to try what someone else suggested to turn off the tailgate lift limiter that keeps it from going up to high (I guess just turning this setting off at the dash fixed their issue). If all else fails I'll just replace the latch/lock mechanism. it looks very easy to pull out and get back on. I found the part for $200 +30 shipping on parts.com
Any input is welcome. I'll be sure to update as I get more into this for others' future reference.
Last edited by testknight; Jul 27, 2013 at 11:31 PM.
Thread Starter
Senior Member
Joined: Jul 2009
Posts: 392
Likes: 21
From: Northern Suburb of Indianapolis
CLS55
All, as mentioned I removed the liftgate interior trim. I found a wide screwdriver helpful here as I would shove it flat between the panels up against on of the yellow or metal trim clips and just twist it to pry the panels away from one another as I gently yet somewhat firmly fulled the interior panel to pop it out,...this helps with not breaking any of them (be sure to use a flashlight between panels and look as you pull out each section...not all areas of the trim pop straight outward.)
That all said, today I loosened the three star headed screws that hold the latch in place to attempt and 'adjustment'. I found it didn't move much, pretty much it would move in or out perhaps 1/8 of an inch. So here I applied force on latch in one direction or another as I tightened each bolt back up.
It took a few tries...once the latch worked but I could not get it to open save from the inside manual release. Another time it worked for a few tests but then went back to what it was doing originally. Each time I would change directions to which I was applying pressue on the latch as I tightened the bolts to keep it in place.
My final attempt seemed to take. I've tested it a good dozen times and each time it stayed locked/latched shut. I did find that some WD-40 seemed to help as well...in fact anyone with this same issue should try the WD-40 first before taking things out just to see.
At any rate, we'll see if this takes. I can see why MB specifically states not to replace the latch as it would seem sometimes it just needs adjusted (moved) a bit...perhaps this is due to the weather stripping seal wearing over time (and thus causing door to be pulled in a bit more than when new...just a thought).
Folks, pretty easy job (I can be a bit wordy, so if I'm not making sense just give it a shot yourself, you'll see what I mean once you get into this). I think I'll have all of 2 hours into this (not including all the time I searched mbworld and elsewhere for very little to no DIY info on this). I suggest saving yourself the dealer 200-250 adjustment or 500+ latch replacement cost (as swapping the part itself looks very easy). Hope this helps someone someday.
That all said, today I loosened the three star headed screws that hold the latch in place to attempt and 'adjustment'. I found it didn't move much, pretty much it would move in or out perhaps 1/8 of an inch. So here I applied force on latch in one direction or another as I tightened each bolt back up.
It took a few tries...once the latch worked but I could not get it to open save from the inside manual release. Another time it worked for a few tests but then went back to what it was doing originally. Each time I would change directions to which I was applying pressue on the latch as I tightened the bolts to keep it in place.
My final attempt seemed to take. I've tested it a good dozen times and each time it stayed locked/latched shut. I did find that some WD-40 seemed to help as well...in fact anyone with this same issue should try the WD-40 first before taking things out just to see.
At any rate, we'll see if this takes. I can see why MB specifically states not to replace the latch as it would seem sometimes it just needs adjusted (moved) a bit...perhaps this is due to the weather stripping seal wearing over time (and thus causing door to be pulled in a bit more than when new...just a thought).
Folks, pretty easy job (I can be a bit wordy, so if I'm not making sense just give it a shot yourself, you'll see what I mean once you get into this). I think I'll have all of 2 hours into this (not including all the time I searched mbworld and elsewhere for very little to no DIY info on this). I suggest saving yourself the dealer 200-250 adjustment or 500+ latch replacement cost (as swapping the part itself looks very easy). Hope this helps someone someday.
