MBWorld.org Forums - GLS Class (X166)

2019 gls450 harsh ride

1xsculler — Thu, 14 May 2026 20:20:49 GMT

I owned a 2007 and a 2012 GL450 and both had a soft cushy ride which I liked very much. This GLS 450 has a ride that is about as stiff as my 2021 Audi q7 and my wife�s 2023 q5 both of which I hated because of it. I have tried all of the suspension settings and it still feels like it wants to knock my teeth out when I go over a speed bump?????

transfer case chain replacement

serb — Wed, 13 May 2026 16:42:02 GMT

not happy with how it shifts so i am going to replace it,this is basically the same chain like on a W164,this doesnt fit cars with offroad package although i read some say it fits,it will be interesting to see how streched it is,you will need around half a liter of MB 236.14 fluid

front lower control arm rear bushing R&R questions

thtguy — Tue, 12 May 2026 12:50:48 GMT

So I saw a video of someone replacing a rear bushing on an R-class (W251) and it bolted to the control arm, ours look similar but look like they are maybe pressed onto the control arm. Just wondering if anyone has replaced just the Rear bushing on the Lower control arms? my front bushing doesn't look bad, no cracks or anything, so I was hoping just to do the rears, but if I have to remove the Control arm and press it, Maybe I should just replace the whole control arm, I know it is more expensive, but I don't currently have a press so I would either have to take it to a shop or go buy a tabletop press.

Thanks!

Rear view Mirror/SOS switch/rain sensor location

invictusmaneo — Sun, 10 May 2026 02:54:20 GMT

Anyone know how/where the rearview mirror/SOS button/lane keep camera/rain sensor section is fused? They are no longer working (buttons don't light up, I get the SOS not operative, automatic headlights disabled message) and I am thinking it may be a fuse issue-I've checked all the ones I can find and checked the fuse diagram but haven't found any popped, so short of that unsure what may be causing it but it's clearly power related. Car is a 2018 GLS63. Thanks!

No boost?

AMGonFire — Sat, 09 May 2026 17:28:19 GMT

My 2019 gls 450 isn�t making any boost. Just running on an all motor car. It�s very slow but drives without hesitation miss fire or any issue. It can get up to any speed just takes a bit. Someone would just think the car is very slow. There is no check engine light or stored code. I don�t know what this could be. Any thoughts?

Coolant leak after couple of weeks after replacing turbo

ssbreddy — Sat, 02 May 2026 17:56:27 GMT

Coolant leak after couple of weeks after replacing turbo. Towed to dealer where the turbo was replaced. On Monday the advisor will call back with findings. I am suspecting they will give a pushback that this is not related to turbo replacement. But it�s not a coincident that the coolant leak started to happend after the turbo replacement. They did not fix something correctly or some loose connection to give way for the coolant pipe burst or something g to loose the coolant immediately after the white smoke started to come from the engine bay near the driver side. See the video attached taken a minute apart. Do you guys think it�s all related to turbo replacement as all these coolant line would have been touched while replacing the turbo.

sorry can�t attach the video but screenshot.

driver door creaking sound

serb — Sat, 02 May 2026 07:21:09 GMT

bad or loose check strap?
door closes like new so hinges are ok i think

License plate lamps

hipjimmer — Fri, 01 May 2026 12:51:18 GMT

Are these difficult to find at a reasonable price? Local dealer has them for $35 each, but out of stock most other places. Rock Auto has them for $9 each, but out of stock. Any other good sources?
2017 GLS.

Can Bus - Short Circuit

ColoradoGLS — Mon, 27 Apr 2026 17:21:01 GMT

I suspect a short-to-voltage issue on can bus. Scanner not communicating with multiple modules. Car running fine.

2019 GLS 450
Original Starter Battery - Napa indicates battery is good. Fully charged on NoCo 5amp maintainer. 12.4-12.6 V
Unknown condition of AUX battery (but no warning lights)
No parasite drains detected.

Car runs fine. No fault codes (but that could be lack of module communication). No warning lights. I do think the battery doesn't hold charge well (maybe loses 0.1V/night, but no parasite drain detected).

I'm using a Youcanic UCAN II C Pro OBD2 Scanner. I am not detecting all the known modules for this car. Example: "no response" on ISM, Transfer Case, Chassis Gateway, etc. Scans performed with key in position 1 (accessory), position 2 (ignition, but engine off), and with engine running.

I suspect some sort of can bus communication issue.

OBD2 check. Battery not disconnected. Door is open (but sounds like system is cycling on and off)

System OFF:
Resistance across Pins 6 and 14 - 60 ohms. [good]
Continuity between Pin 4/5 (ground) and Pin 6 - 0L open line [good, no short-to-ground]
Continuity between Pin 4/5 (ground) and Pin 14 - 0L open line [good, no short-to-ground]
Here is my problem (I think)
System Off: Voltage across Pins 4/5 and 6 (~11.5)
System Off: Voltage across Pins 4/5 and 14 (same voltage as on Pin 6)
System Off: Continuity check Pins 6 to 16 (power) - 0L open line [good, but I understanding a short-to-voltage may not run back to Pin 16]
System Off: Continuity check Pins 14 to 16 (power) - 0L open line [good, but I understanding a short-to-voltage may not run back to Pin 16]

System ON (engine not started)
Voltage across Pins 4/5 and 6 (2.5V-2.6V) [good, turned on but maybe in standby mode - not actively transmitting data] - not using an oscilloscope
Voltage across Pins 4/5 and 14 (2.4V-2.3V) [good, turned on but maybe in standby mode - not actively transmitting date] - not using an oscilloscope
System ON (engine running)
Voltage across Pins 4/5 and 6 (2.6V - can HI) [good, transmitting data] - not using an oscilloscope
Voltage across Pins 4/5 and 14 (2.4V - can LO) [good, transmitting data] - not using an oscilloscope

Questions:

1) I suspect a short-to-voltage on the Can bus Hi and Low. Is this likely correct?

2) If there is a short-to-voltage and I only get a "no response" on the scanner for modules that I know should be on the car, do I need to worry about this if the car is running fine and the system modules are working? Basically, I know tracking down a short-to-voltage can be tedious.

3) If I do need to track this short-to-voltage down, does anyone have the can bus locations for a 2019 GLS 450? I understand one or two may be behind the front passenger kick panel. I figured I'd start with disconnecting the modules at the can bus and rescan to see if I can find the faulty module pulling down all these other modules.

4) Do I just need to sit down and shut up and enjoy a good driving car?