Chasing few issues.Right now working on liftgate as it doesn’t work. It locks-unlocks,
(only when car is off key removed) and will pop open with remote then have to manually lift it. Automatically locks when you start car. Door button has no effect. And the push button in rear doesn’t light up or work.

Doesn’t sound like a pump issue,possibly electrical. If anyone knows where the rear button is tied into for power?And is the liftgate module sitting on top of the hydro pump under spare tire.

Don’t think it’s related but possible,ALL the door locks don’t work from door switch or remote. Alarm does remote arm.Is there a primary module for all 4 doors or is it tied into a Sam unit?Anyone know Wich 1 and its location. I know each door has a module buts it’s impossible that all 4 went bad together.

If the same computer controls the electrical signal to tailgate and door locks Im going to start with changing that.If not I’ll swap whatever modules you guys point me too.

Appreciate any help,
Thanks

 

Do you have a bidirectional scan tool?

start by interrogating the modules under chassis.

The one that doesn’t communicate is likely the one that’s fried.

based on your symptoms, I would say rear Sam

 

Do you know if anybody has replaced the struts on that liftgate? If so check the wires on the struts of the liftgate and verify their Mercedes oem. Beyond that you're going to want to verify that the accessory battery is fully charged. I have run into both issues on various different Mercedes wagons GL and in almost every instance it turned out to be a bad passenger side rear strut Electronics which was immediately resolved with real oe struts

Voice text...

 

These liftgates use a hydraulic ram and arm to open and close the gate, not a linear actuator in the strut itself. You can see the arm on the passenger side of the upper gate, under a rubber boot.

 

Having replaced those (twice) recently on our GLS. The one on the right (pass side) is not hydraulic at all, it is a screw lift. if that lift has failed the switch in the door will "do nothing" unless the code is cleared. Once cleared it will try a time or two and then error out and again seem dead. I got a cheap lift (Amazon) that lasted about three openings, maybe four. Then ordered Stabilus brand lifts and since then it works as new.

 

You are posting in the GL X164 (2007-12) forum. The GLS is from 2019 on.

 

Same setup - there are electronics in the right side (Pass). In general that is the failure, no need to search fuses and electronics if the basic first steps are not taken. Occam's razor.

 

Why do we keep getting guys dropping in that have no idea what they're talking about.

 

Sadly I don’t have a good scanner yet. I had a mechanic with a good scanner diagnose it he found the central gateway bad under seat.I replaced it and my signals wipers etc. came back on.

He said he is sure there is another computer bad but he’s clueless wich 1 it is. And I don’t have the money to pay a shop. I figured I’ll change whatever computer controls the door locks and liftgate and start from there. But neither of us know wich 1 does. If the rear Sam controls them I’ll change it. Do you know where it is?Is it the 1 on passenger side quarter panel behind the fuse box under the sub?
Do you happen to know if it controls both the tailgate and door locks or just 1 of them?

Thank you for any input

 

Not the same setup.

 

There are goofy little computers all over the place. I installed a Chinesium driver door switch panel and it (I believe) fried the little computer attached to the driver door. See, the door switch panel only has three pins on the output, presumably power, ground, and signal. It sends that signal to a computer riveted to the door, which then communicates with whatever computer actually controls the windows and locks.

I believe you are correct about the location of the rear SAM, but I have to warn you: Playing parts darts with electronics is a terrible strategy. Practically speaking, you can only install used parts, and how will you know those used parts are good?

Your alternative is to get a bootleg copy of WIS and use the electrical schematics to trace the fault.

 

By the way, while a bidirectional scan tool is ideal, and will set you back about $800, you can get good read-only scan tools for about $200. The MBII appears to be quite good, and there are others that are general-purpose and thus have more widespread utility.

 

For what you’re doing, you might need the ability to code VIN into modules you’re replacing.

the primary use though is to troubleshoot by interrogation vice firing a parts cannon.

even cheaper is timed access to WIS, which will answer all the questions on where each module physically is. I’d start there.

 

Very true it’s kind of senseless to swap
parts to chase a issue.But I found a junkyard with 3 intact Gl and 1 ML.People wait on
these to land In the yard and they go to town on them removing every expensive computer and part. There is still 2 almost complete and I was going to grab the rear Sam and whatever else I can take off. And I believe I might know where the rear hatch Module is. I seen a video of it on passenger side wall next to rear door. Its grey and looks big like Rear sam. I believe this controls the red hatch button.

I was going to buy the Mb II scanner but it seems it doesn’t test individual modules and will just give you codes.If it is intelligent enough to say wich module is bad rather then say there is no communication with 4 modules I’ll buy it if someone has 1 for sale here.

Why I think it’s the rear Sam is the red light doesn’t come on the hatch button. If it was pump then it would still light up or even attempt to lift. It does lock unlock and pop open but no up n down. It’s dead.

Same with the doors. If it was say door module then I would atleast have some of the door locks working but their all dead. There was a new key made but I doubt that is the cause. I can’t say if they worked prior to new key. That shouldn’t effect interior lock switches.

I will post what codes I have been able to pull with the cheap Bluetooth tool I have. Only 4 engine codes all related to cam sensor wich I believe is timing chain related as this is the 07 model.

Many door codes as well as other ecm. I think 1 or 2 computers are causing all the codes due to no communication.

what we have replaced so far is central gateway. Wich fixed the no signal wipers etc. issue. It still gives codes for bad gateway but maybe because we couldn’t reset the codes after installation.
And He did not program it to car said it didn’t need to be. Replaced amp and command Audio works again. These were bad from water intrusion wich I believe maybe is cause of these other issues in rear modules.

The car sat with a bad battery and needing jumps
for several years. New main battery installed. Have not put new Aux bat yet but I don’t have check battery code either. Most of the codes you see say low voltage so I believe these were mostly triggered from bad battery and jumping the car








at the time.

 

I owned a MBII in 2020. It was able to interrogate individual modules. If you are looking for a Shell Answer Man in computer form, nothing will satisfy you.

To be honest, I think your wrecking yard has three intact GLs.

 

So, couple few observation here:

-a bad tool is worse than no tool, as it will lie to you. That being said. All the low voltage/garbage codes are related to a failed battery. Clear them out and read out those that reappear.
-aux battery matters not if you have a good main battery. All it does is provide voltage to the ism to shift the vehicle out of park so that you can move it/tow it in a failed main battery condition.
-get the vin from every car you take a module from. You will likely need that to divorce the part from the previous car before you marry it to yours. Lucky you to have that parts access.
-WIS access via startekinfo is critiical here as it will spell out what to do in your particular fault situations.
-check your cars motor number using online vin finder and compare against affected range of m273. If your valve train adjustment codes persist you probably have no balance shaft sprockets left and the motor needs a full valve train rebuild.
-if you’re able to take a free GL with multiple fired modules back to serviceable condition for less than $4k in parts you are money ahead.
-if you need labor and parts in excess of $4k to include a known good used motor, you are effectively throwing good money at a parts car. I can pick up a multiple 08-09s in need of rear air springs for around $4-5k around here in the PNW, most of them are dry inside.

vin decoder:
https://www.lastvin.com

affected m273 range is engine number less than

• M273 Engine Serial No. 2739..30 088611