Here you go my man....
The ones hard to find.

W70 & W9 Ground Points - Front Engine Bay - Left Side - Remove Wheel Well Liner




W2/1 ground point for my Right Hand Drive


W2/1 ground point - If Left Hand Drive





NOT* Documented by MB ( *as far as I tried hard to see all Ground Points document ).
Main Ground Point To engine block near starter. I dont know where is a LHD starter position. My RHD starter is on the left side of engine block.



For ECM grounding, M276 3.5L N/A is different than mine 3.0 TT , so you got to look at the top post Ground Points docs.

Good luck....

 

I think I shall report the investigation of Low Voltage of Control Module aka ECM/ECU akan N3/10 here, instead of a new post.

The special custom tool I made. The T15 torx is from a screwdriver version. Top part is 10mm hex. Top part is machined by a shop, US$11 only for labor + material hahahaah. The T15 Torx screw driver US$5 including shipping... LOL.

https://www.monotaro.id/s025006063.h...RoCn9wQAvD_BwE


First 10mm loosening using my special tool and passed that point the long L T15 can be used at an angle.



This one rather tricky. Final loosening using my fingers... LOL.



Maximum lift of N10/1 I can do, that's it. At the least my inspection camera has room to work.








All 3 power feed wired at N0/1 seems tight. There is nothing more I can do.



Power sensing from :
F27 fuse, the power feed for N3/10 ECM/ECU.
F11 fuse, because it is easy to access
Both positive feeds are protected with a 2 amp fuse.



F27 Fuse wiring




F11 fuse wiring




The mini mobile studio + bench test ....



Negative feed for the Flukes is from direct battery negative post at suspension well.
Even though it is negative, I still fused it for safety.... just in case it stray to a "+" item.




Will continue.................

 

Imagine, Battery Sensor at battery, which is UB in MB instrument cluster, is already reading low 12.3 Volt.
Torque App's Volts (CM) ( Control Module ) shows 12.2 volt. Fluke 289 which is 1 wire upstream of Control Module / ECM / N3-10 is also reading 12.221 volt.
Fluke 189 is reading 12.27 Volt.
Torque App's Volts (Ad) which is from rear SAM N10/2 OBD2 power is reading 12.4 volts. Could be some capacitor in the N10/2 electronic board assisting this power feed.... I am guessing.

To understand how the Torque App's Volts (CM) ( Control Module ) can go as low as 12.2 volt, you need to see the video to witness how carelessly
the discharging algo is being executed. Such a long drain period. Damn....



Now, below could be a local fast power draw ( like a surge, inrush ) at Control Module / ECM / N3-10, while discharging is occuring at that 21.9 amps IB.
Torque App's Volts (CM) ( Control Module ) at 12.2V ,which is actually 12.227V as per its CSV log.
UB in MB instrument cluster showed 12.5V , Fluke 289 showed 12.440V and Fluke 189 showed 12.52V and Torque App's Volts (Ad) showed 12.5V



Next.... another power surge ?







Next....






Well, I can rest my case now.
Unless there is any easy but robust way to upgrade the 0.75mm power feed wire to ECM to a 1.5mm one..... I don't see how more I can improve/reduce the voltage drop at ECM.
Good thing the extra & more direct grounding wire has produced 0.2 volt overall less voltage drop. At the least something good came out of this long tiring test.

.

 

the big question is: what is causing this unstable yoyo when a known good alternator stops maintaining 12.6V ?

I see this happening after the quick charge cycle is complete when R-SAM takes over ALT Mgt.
It's like R-SAM measurements are skewed and makes it acts bizarrely.

Based on what we've seen, I am tempted to concentrate on the R-SAM power distribution: PCB traces, GND, Wiring, heat stress... I will rest easier when I have checked R-SAM for the amazing "solderless pins" I found in other modules.

 

Can you describe the "solderless pins" ? Photos will be nice. Thanks.

 

I gave a long thought for this ECO charging algo, from a different perspective.

My hypothesis as follows :

The weakness aside from poor write-up/content* (*whatever the proper term is for making a software) of the algo is also the slow speed of the LIN bus used.
https://www.csselectronics.com/scree...cs/language/en

Hyundai battery sensor B95 reports to rear SAM using LIN bus.
Rear SAM talks to Front SAM on the CAN bus.
Front SAM talks to alternator on a LIN bus.
So its a LIN>>CAN>>LIN data route. LIN is always choosen for the lowest priority equipment. Imagine, in this day and age 1-20 kbit/s is STILL slower than our long forgotten 56kb/s dial up modem.
We also do not know the update speed of the Hyundai battery sensor reporting ??

I highly doubt the algo takes into account feed back of local low voltage situation/event from other modules, during the long and high discharge.
Looking at the level of allowed YoYo voltage dip, Hyundai battery sensor seems to be the sole data input for the algo.

The dumb azz side of the algo is quite clear.
Why allowed, albeit only for a few seconds..... amps hour discharge to 50% of a battery rating, 45 amps is 50% of a 90 AH battery ?
0.5C discharge is easy for Lit-Ion but I would not call it wise for lead acid or AGM battery with proper alternator support.
Our "wet" battery is known for its slow charging acceptance and quite a low efficiency during charging.

So we go back to the simple voltage graph available to us : Below is June 10 log, the same data as my latest report. Test started with battery fully charged.


For simplicity sake, we take 12.7V as neutral , no charge or discharge.
Even if assuming the up-s/charge and down/discharge and amperage is equal both ways, I still loose out to battery limited charging acceptance and charging efficiency.
This ECO charging algo is way too reckless. I think a battery company made the algo , so more battery sales.
Not only in terms of the YoYo voltage from 14.8V to the allowed discharge of 12.2V , the charging amperage high magnitude albeit short burst is not good for battery longevity.
2.6V swing out of a say 13.6V as reference ( float charge ) = 20% , not nice.
For all the computer modules on our car, good voltage stability should be the priority. Aha.. so the algo is a joint venture effort between modules & a battery company ??

Reminded me like the old days 45 years ago, my bicycle using wheel generator for the lights... LOL.

 

As much as I can tell Mercedes likes to engineer business opportunities, yet I am not convinced about this problem because we don't know exactly what triggers it or how to prevent it from happening at all. I've witnessed my car @11.7V on the freeway

I personally don't think "Engine Cut Off" requires to drain batteries while driving. It does require 14.9V "quick charge" for rapid Stop-'n-Go cycles.

By now... I wish there could be a TSB pointing to the cause

Actually there is a subscription service for mechanic shops to gain knowledge about these common nightmare's. Something called idx or similar...
Clowns are suposed to waste their resources untangling managed chaos.
- SA: "We couldn't reproduce this"
- MB-USA NY: "you're the first one!"
🤗

-----
Wish I had a running Xentry to step through conditions

 

There is a battery sensor recall, different P/N, but also a Hyundai Mobis Battery Sensor, for C class BR205/253 upto 2016, which I believe uses the Anti Voltage Dip Capacitor instead of 12 Ah battery at trunk.
https://static.nhtsa.gov/odi/tsbs/20...58373-9999.pdf

The effected Bat Sensor P/N , difference to our W212.


By the way the issue is explained :

Cause:
Error in the calculation of the charge balance and the state of charge of the battery that causes an unjustified message
in the Instrument Cluster display

Screwed-up algo seems to be the case , not hardware.

 

I'd like to report two more ground points in your collection.
Today I went out of my way to meet CGW/Distronic modules and was greeted with 2x GND points (co-driver footwell).


footwell stashed GND
​​​​​​
Quality was similar to what I found in the trunk: semi-isolated on both sides.
A paint lip on the nut side, a layer of dirt on the strap and the stud shoulder.


crusty post

dirty strap contact
​​​​​​
Next time I will try to measure the resistance before fixing the GND point. I don't believe in measuring anything I expect below 1Ohm without a special setup. So I just fix them.
​​​​​​
------ EDITS 1:
I am ready to consider the brownish residues on the stud may be some type of Benz magic ground protectant yadi-yada... but the thick lip of body paint on the nut side: it's only isolating.

------ EDITS 2: low power CGW sharing GND with heavy gauge cables...
Most GND points are shared by many circuits. When the connection resistance is borderline unsatisfactory and a heavy current is seeking GND, the other circuits get disrupted by GND being above the 0V rail... transient CAN and DTC's.

 

I have not done any interior ground points survey yet .... thank you Cali.

 

today I came across 2x more GND in trunk worthy of attention. 1 rear right side, 1 front left side. I believe this completes trunk modules GND.
(Trunk total: 4 + AUX)


trunk rear right side: standard repair

Go to the obvious 1st:
It's faster to fix all GND than trying to trace circuits across mutiple diagram screens -
Spend time... to save time 😃

 

Yep, that's seems to be all I have too for grounding points at trunk.





There was a video I saw, a W212 trunk and that car has an option/hardware where I drew red rectangle below. Hidden under the dark grey colored plastic. I wonder where that device take its ground.

 

yep, the trunk area is now familiar territories with all good clean GND (3 loose pins modules) for taillights, Audio Amp, R-SAM, keyGo, RFK.

Next stop:
driver footwell (US LHD)... hopping to find GND points for all the central console units and a few extra VIP modules -

Hopefully I won't disturb any SRS

GND points are my top most priority because they affects A to Z with dropped voltage surge under load. GND are stupid enough we don't want sniky troubles from them..

Do you know if the trunk lid itself is grounded
-or if all GND are individually wired for: lights, latch, RFK ???

Have you seen what modules are installed under rear seat besides mBrace ???
😆

 

My car has no Mbrace ( internet to MB ) or any phone feature, except the common bluetooth phone over the sound system head unit.

There was a case, I saw on youtube, Mario Super Diagnostic, where a W212 E350 with what I believe is using Mbrace/Emergency Call feature was trying to update over the air and owner may have ran out of
subscription. So car was draining battery all the time because the CAN was running 24/7 ... LOL. There was a TSB on it though.

 

was listening to Julian Lage's new jazz guitar album on Spotify to USB android auto to the Harman Kardon system in the E350 wagon while I cruised around the beach this afternoon, and it sounded really really good.

https://open.spotify.com/album/4eomO...1g&dl_branch=1

 

Try to get this recording in its native DSD form :
ALBUM : A Toast To Julie London
By : Lyn Stanley
Format : DSD
Even when converted to MP3 320kb/s it sounds real good in the W212 Harman. I use USB stick for the W212.
Its the fine detail of the musical instruments I love, but best listening will be when you are parked or using a home stereo.
Noteable ones I like because of the instruments : Summertime, Cry Me a River and Sway.


Diana Krall is not bad too. Her voice is unique.
ALBUM : Wallflower , 2015

Enjoy....

 

saw diana krall live a few years back. thought she was a little too derivative.

mostly, I listen to americana and roots stuff.... I just dabble in jazz, especially jazz that overlaps said american/roots music.

 

behind E brake on the firewall

The usual fare I've come to expect...
Next GND candidates are under both front seats, central console and IC display after I complete all the hood locations (Left wheel well for 100A Fan, behind battery tray, headlight ballasts).

Steering GND nut all cleaned up & ready

Steering GND was under hood on passenger side with standard fare.

 

Sweet......

 

At 7min, Ivan shows a ground cleaning tool provided by a viewer.
Pilot Bonding brush. Great for bolt into frame connection. Unfortunately many MB grounds are nut onto frame bolt connections

 

I’m so glad I found this thread. Amazing work.
could you point me in the right direction of my passenger headlight ground?
I’ve changed the ballast and hid bulb and still doesn’t work. I’ll even send you some money to help me figure this out.

 

MB headlight variants are plenty, you need to use MB vin decoder to get ur headlight type/code and then the specific wiring diagram for it based on your chassis code, assuming it is other than W212.
Use this vin decoder : https://www.lastvin.com/

Example, my headlight is called 641 Dynamic LED, which is ILS and latest facelift LED.
So I need to find the wiring diagram for 641 headlight and since my car is a 2014 model year and a facelift one, the Front SAM and Rear SAM wiring diagram, I must choose the section where
it is a facelift model one. MB model year as sold is not the same as car production year, albeit mine is a model year 2014, the production date is 2013, I believe it is august.
So I then use my car year of production date to choose which section of the wiring diagram is for my car for Front SAM N10/1 fuse box ( has computer and gateway too ) and also rear SAM N10/2.

Here is an example of how much migrain a Front SAM wiring can generate
https://mbworld.org/forums/e-class-w...10-sheets.html

The first post of this thread has all the ground studs/point at the engine bay LEFT and RIGHT side, that you should use as a tool.

I am away in Bali till mid Jan 2024, so I can't accgtess my WIS/EPC which is on my home PC in Jakarta.
When you get the headlight code/model of yours, you need to request wiring diagram for it from this forum, hopefully someone will search for you.
The search in MB WIS is not so easy, MB WIS is so bad in terms of its search algo..... even I get frustrated often and I have used it often enough already.

I don't want your $$, if I can help.... I will help

 

really appreciate the information.
I checked that website and this is my headlight
BI-XENON HEADLICHT W.ACTVIE CURVELIGHT RIGHT-DRIVE
2012 e550

 

you're trying to publicly bribe our Master? He's just going to give your tips to his family driver...


Your painted HL GND are located at the front, hidden under each chassis beam.

Disconnect all battery power before surgery.

Not to beat a dead horse but GND are essential for everything. MB decided to give us incentives to survey our cars.


salty undercarriage GND single strap.... SERIOUSLY?!?

Fixing ALL GND Posts is a great idea starting with main chassis strap that is clearly built to fail. Our computers don't need extra glitches.

 

What is the code ? 6xx ?

Here is a :
608 AUTOMATIC HIGH BEAM SWITCH (IHC)
615 BI-XENON HEADLICHT W.ACTVIE CURVELIGHT RIGHT-DRIVE
Go take a look at the wiring diagram, post #14 https://mbworld.org/forums/e-class-w...ml#post8464145

W9 ground for E1, E1 means LEFT side headlight.
The E2 headlight may use other or closer to it ground stud.

You must also test to make sure the +12V is there and can take the load. use 50 watts halogen to test.
From that small portion wiring diagram , your headlight is driver/electronic driven and not a simple mechanical relay and is from N10/1 Front SAM.

Have fun troubleshooting.....


To note :
MB way of naming their options in data card, for early car can be confusing when we use the wiring diagram.
The word Bi-Xenon in headlight code 615 becomes only XENON in wiring diagram and sadly the headlight code is not mentioned in the wiring diagram, unlike 641 dynamic led .

Somehow there is a disconnect between sales people and engineers who make the wiring diagram title.
Also we must understand that in 2009 when this car were first introduced, wiring diagram engineers would not know what variants of new headlight or even engines later down the years.

I am having the same problem for my engine which is M276.8 3.0 turbo, where before this turbo engine was made available, it was M276.9 3.5 NA.
Many older than 2013 documents, would assume M276 was the only engine and I sometime got sucked into this problem by having a WIS auto page connect, linking me to
M276 engine which means M276.9 and not M276.8. Sometime me got to make a guess.... sometimes.

The same with ECO start stop. From code B03 with baby 12amps battery at the trunk, some later W212 of say 2016 will get a capacitor instead of extra battery.
Anti voltage dip capacitor it is called.

The facelift cars wiring and more so the most uncommon engine like mine, is like a pariah.... information get buried deep and hard to find in WIS.