GL Class (X166) 2013-2015 after facelift became GLS (X166)

Tailgate Unresponsive

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Old Dec 21, 2021 | 05:57 PM
  #1  
Jason Stewart's Avatar
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Joined: Feb 2021
Posts: 68
Likes: 12
2013 GL550
Exclamation Tailgate Unresponsive

After a cold evening, this morning my rear access / lift gate / tailgate / hatch / boot became unresponsive: it will not open from the key fob, driver's door button or exterior rear access button (above license plate). It makes no sound (mechanical or beeping). I am searching for a diagnostic procedure (and ultimately a fix).

I have tried the following fixes detailed in this forum without success:
  1. Checked fuses
  2. Adjusting ambient lighting level to 5 or disabled (funky software issue)
  3. Disconnecting the main battery to reset
  4. Trying to manually set the opening height (another trick)
I am able to open the tailgate using the physical key access hole on the interior of the tailgate.

Once open, I can lift the tailgate to any height and press the close / lock buttons and they perform their anticipated functions. Also, once opened manually, I can press the exterior rear access button (above license plate) and the tailgate will continue to open on it's own. This seems to indicate that the motor to open / close the tailgate is working normally.

Once open, I can also manually trip latch (tricking it into thinking the gate is closed while it's opened) and I can see the latching mechanism clamp then tighten (as it would if it were latched to the real lower latch). This seems to indicate that the latching mechanism is working normally.

Questions:
  1. Does anyone know how to reset / reprogram the tailgate control module?
  2. Anyone had similar issue and discovered a fix?
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Old Dec 21, 2021 | 09:25 PM
  #2  
Ntuck's Avatar
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Joined: Aug 2013
Posts: 156
Likes: 7
2014 GL 350 Bluetec
Originally Posted by Jason Stewart
After a cold evening, this morning my rear access / lift gate / tailgate / hatch / boot became unresponsive: it will not open from the key fob, driver's door button or exterior rear access button (above license plate). It makes no sound (mechanical or beeping). I am searching for a diagnostic procedure (and ultimately a fix).

I have tried the following fixes detailed in this forum without success:
  1. Checked fuses
  2. Adjusting ambient lighting level to 5 or disabled (funky software issue)
  3. Disconnecting the main battery to reset
  4. Trying to manually set the opening height (another trick)
I am able to open the tailgate using the physical key access hole on the interior of the tailgate.

Once open, I can lift the tailgate to any height and press the close / lock buttons and they perform their anticipated functions. Also, once opened manually, I can press the exterior rear access button (above license plate) and the tailgate will continue to open on it's own. This seems to indicate that the motor to open / close the tailgate is working normally.

Once open, I can also manually trip latch (tricking it into thinking the gate is closed while it's opened) and I can see the latching mechanism clamp then tighten (as it would if it were latched to the real lower latch). This seems to indicate that the latching mechanism is working normally.

Questions:
  1. Does anyone know how to reset / reprogram the tailgate control module?
  2. Anyone had similar issue and discovered a fix?
I had this happen years ago and I had to take it to the dealership to get it fixed. This was when it was covered under warranty. I can't remember what they said was wrong, but they were able to fix it right away.
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Old Dec 22, 2021 | 03:21 PM
  #3  
scuba steve-o's Avatar
Junior Member
 
Joined: Jul 2021
Posts: 21
Likes: 3
gl350
Originally Posted by Jason Stewart
After a cold evening, this morning my rear access / lift gate / tailgate / hatch / boot became unresponsive: it will not open from the key fob, driver's door button or exterior rear access button (above license plate). It makes no sound (mechanical or beeping). I am searching for a diagnostic procedure (and ultimately a fix).

I have tried the following fixes detailed in this forum without success:
  1. Checked fuses
  2. Adjusting ambient lighting level to 5 or disabled (funky software issue)
  3. Disconnecting the main battery to reset
  4. Trying to manually set the opening height (another trick)
I am able to open the tailgate using the physical key access hole on the interior of the tailgate.

Once open, I can lift the tailgate to any height and press the close / lock buttons and they perform their anticipated functions. Also, once opened manually, I can press the exterior rear access button (above license plate) and the tailgate will continue to open on it's own. This seems to indicate that the motor to open / close the tailgate is working normally.

Once open, I can also manually trip latch (tricking it into thinking the gate is closed while it's opened) and I can see the latching mechanism clamp then tighten (as it would if it were latched to the real lower latch). This seems to indicate that the latching mechanism is working normally.

Questions:
  1. Does anyone know how to reset / reprogram the tailgate control module?
  2. Anyone had similar issue and discovered a fix?
I just had this happen the other day in the bitter cold.
I had to access like you, from the inside with my key, and pop it open.
Once i did that i used a compressed air can and sprayed out any crud in the area, and lubed up the locking mechanism/latch. I manually opened and closed the latch several times using my key, all while lubing up the area as much as I could.
Seems to have fixed it and opens no problem now. The plastic that the latch would rub against, seems to have caused too much friction and wouldn't move anymore.
Hope that helps your situation.
Reply
Old Dec 23, 2021 | 11:05 AM
  #4  
silvergl's Avatar
Senior Member
 
Joined: Oct 2018
Posts: 255
Likes: 77
From: New Jersey
GL 450
I replaced the module on mine, not too bad of a job, about $300 part if i recall. Then i read that there is a software repair that could of fixed it, recoding the module or similar.

I took apart the door, did all the expected steps including the motor, in the end the module fixed it without going to the dealer.
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Old Dec 23, 2021 | 07:06 PM
  #5  
Jason Stewart's Avatar
Thread Starter
Junior Member
 
Joined: Feb 2021
Posts: 68
Likes: 12
2013 GL550
Thumbs up Resolved!

Thank you to everyone who provided advice!

By some miracle, our local dealer was able to get me in to diagnose same-day. I told them about the software update, which the car needed and they performed, however it did not resolve the issue. Ran diagnostics, found codes for rear latch, then they took apart the tailgate housing and found that the latch was "popping" (releasing) when the buttons were pressed (no sound from it all). A second miracle occurred when the dealer actually had the replacement part IN STOCK! It took them 1 hour to diagnose and replace the part. $450 but glad to have the use of our tailgate again in time for Christmas.

I'm guessing could have have saved 50% (or more) in cost if I could have diagnosed and replaced the part on my own ($100-$150 on eBay) but was willing the pay the premium in order to get it done quickly for use during the holidays.
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