Simplicity can help many savy members improve engine + tranny basic driveability.

Only work on this if you have Xentry or a MB compatible scanner to read your module fault collection.

The issue this solve is not surging the chassis while fastening the MainGND brass nut - We don't want surge!!!

We're going to repurpose an old fashioned jumper cable. We'll use it to momentarily connect MAIN BATT(-) with the ENG GND (-) while dealing with main connections.


BLACK side ONLY - RED remains UNUSED 👍

Again we are only dealing with BLACK/GND/(-) at all time. We are NOT dealing with RED/PWR/(+) stays unused for our purpose.
​​​​
> WARNING:
- This is experimental and may be dangerous
- Don't try this at home...
- Do not contact to Red (+) battery at any time
- This is entry level once you understand a bit
- Do not run engine with any cabling near belt/fan

If you are confused: dismiss yourself from this experimental procedure.
Invisible electric power can become dangerous regardless of voltage.


> POWER DOWN (1_Aux/2_Main):
Chassis is going to loose power in a controlled way without any surge sparks.

1- PRELIMINARIES:
We are going to first install a GND bypass before anything else.

Clamping GND on MAIN BATT(-)


Clamping GND (-) on M276-3.5NA engine aluminum

> At this point main GND is directly connected via our bypass setup...
We can proceed further with disconnections


Removing MAIN BATT GND(-)


Removing the now bypassed unused GND Post... no current: no spark: no problem!

> At this stage Main remains fully connected via bypass only.


2- AUX OUT:
Let's first disconnect the AUX backup power

Trunk AUX disconnect
(10mm wrench or quick disconnect shown here)

> At this stage without AUX, the chassis remains only powered by MAIN.... let's go back at the front near engine strap.

3- MAIN OUT:
Proceed to this step in less than 30seconds after AUX.

Remove GND clamp from engine at once

Now the chassis has lost all power except BATT LIN Sensor...

4- HYUNDAI OUT:

Unplug the Hyundai BATT Module to manually cause batt relearn.

Now take a 15mn break or longer..Refrain from shorting (+) to (-): the whole procedure helps avoid surges - So pls don't create unnecessary surge that undersized capacitors are going to dislike.


> POWER UP (1_Main/2_Aux):
Chassis is going to power up in a controlled way.
We are going to limit production of sparks to one snap.

1- MAIN BYPASS ON

clamp the GND in one quick snap
That's where you're going to get one small current surge to power up all drained sleeping modules.

2- HYUNDAI BACK IN:

Front Batt sensor is now connected back to Rear-SAM LIN in charge of managing the 12.6V Float voltage based on consumer demands.

3- TRUNK AUX BACK ON

AUX is now back on within 30 seconds

4- MAIN GND BACK IN

reinstall MAIN BATT Strap
No current, no spark, no surge!



Fasten the brass nut with hand torque appreciation

5- BYPASS GND REMOVAL

bypass strap comes off
no current, no spark, no surge!

Falks, there you have it. (Car Care Nut)
Nothing less nothing more. (master Tasos)

> AFTERMATH :
There is very little negative side effects to loosing power on this chassis and so much to gain!

reverse gear: mirror tilt: driver door switch
Windows control: driver door switch
Clocks /Radio automatic!!

There is NO AGGEAVATION with...:
COMMAND CODE : not needed
Windows/roof reset : not needed


> IN ADDITION:
This batteries procedure is perfect for...:
-- winter month storage
-- AGM higher voltage charge cycle
-- Wild chassis gone sleepless (CAN-B)
-- Numerous delays in sloppy tranny shifts
-- Clunky engine affected by CAN latencies
-- Removing modules out without power


-- Results may vary according to how fast networking chaos overwhelms CentralGateWay. About twice a month or weekly is a fair amount of time.

-- You will notice a better throttle response temporarily while network chaos is reduced.

-- You should learn to your IC display to show the Hyunday sensor data. That will help you evidence any live chaos brewing.
-- On the road a Key "On/Off/On" cycle will help you quickly reset limp-modes after prolonged drives.

Enjoy your journey with serenity.

Great write-up!

Cali, that blue circular plastic thingy, what is that ?

This is a "quick battery disconnect" sized for motorcycle batteries.


I could not find a satisfying "quick disconnect" for the main AGM so I just undo with the tall brass nut at chassis end of batt strap.

This reboot procedure is used during experimental ALT-LIN MOD to cancel variable voltage.

I see, mini battery switch.

yes, that's what a battery disconnect is.

a giant manual switch with large contact to pass current spikes.

We know AUX powers whole chassis minus starter during crank. That's about 40Amps - Actual load is reduced by R-SAM for that purpose.

This disconnect does the job.

@CaliBenzDriver do you have 1 battery in engine compartment and 1 in the trunk? because in w205 i have one little AUX in passenger foots only or at least i never seen battery in my trunk :O

Yes the W212 Facelift model has both:

1. large MAIN AGM near engine
2. small AUX AGM in trunk

To reboot you need to disconnect both batteries as the AUX will deliver power as soon as MAIN goes out of circuit.

Your chassis has an in-dash small AUX to power the ESL steering lock...

> NOTE!!:
Earlier chassis may forget settings of Windows, clock, radio mems, seats, sunroof... that will need to be retrained using a scanner or chassis specific procedures.

For the W205 and the C-Class sedan, it is usually where the cabin air filter is which is underneath the front passenger foot well beneath the glove box.

Well, technically it is beneath the cabin air filter, anyways that video should show the exact location.

yep i was about to change it 2 yrs ago when msg appear on my cluster but i put new aux battery and msg was still there and then i plug back my old one and changed the main battery and msg from IC dissappear

so do we just disconnect our AUX in the foot passenger side for the procedure, because compared to Cali one our is several times smaller

Mhmm : )

Cali i do have few questions will make them with numbers easier for you and others as well to follow up

******
1. I don't have any scanner, so if i do this procedure without scanner is this going to be an issue?
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2. I guess for M276TT is same place where we should clamp GND? (I guess so but i prefer to ask)
******

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3. Removing GND clamp at once is that means from the engine and the battery or just the engine?
******


******
4. so we unplug this cable from the sensor which is in the GND but we never remove GND from battery?
******

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5. Clamp GND in quick snap at once to the engine and battery or just to the engine and leaving the other side of the cable somewhere where is no metal?
******

THANK YOU

Good questions Kistiyan,
my answers within your questions.

The whole object of this procedure is to prevent surging fragile computers while tightening the loose GND.

im thinking for a long time to buy some budget scanner and yet didn't pull the trigger..

thank you for the simplicity as well, so i guess when i unclamp ground for short period from the engine till i have to clamp it again i should leave it somewhere where have no touch with metals just in case? : ))

exactly: don't let the loose GND clamp kiss any besides plastic. (It's a zero volt GND... but live not referenced to chassis).

A lot of us seriously enjoy using $150 LAUNCH CREAFER ELITE MB ... the reports are very useful to understand faulty modules interactions.
Without a comprehensive report, cryptic faults are misleading.

As Cali says, ">> ​​Don't be "caught with your pants down."

Currently, the best small yet powerful Mercedes scanner is the LAUNCH Creader Elite 2.0 BENZ! At approximately $160 on Amazon (and only $129 on KingBolen), there is absolutely no reason not to have one.

Thank you for the suggestion Cali : ))))

Thank you for the screenshot as i get confused by other readers as well, i just found it in AliExp. for 129$, when i select MB is that means if i plug it into VAG car it will not work at all?

LAUNCH does offer the BBA version where you get Benz, BMW, and Audi programs included. It's $10 more on KingBolen.com.

If you connect to a car without its program, you can still use the generic OBD function. Alternatively, you can download the vehicle program through the Mall feature. However, extra vehicles run about $60 per year subscription. That's why if you have a BMW or Audi, as well, it pays to get the BBA version since those programs do not require a subscription.


https://www.kingbolen.com/2024-launc...ba-code-reader

good to know thanks very much, probably would pick it up from this website so i can be sure i order right one

JR! $139 is a great price for the combo unit.

This is an excellent tool to get a complete PDF report without dealing with XENTRY complexities.

Back during the holidays, it was at $109 and I couldn't help it. So, I have the BENZ only version for the C350 and the BBA version for the SL400. I keep one in the Rear SAM cubby of the C350 and one in the storage cubby behind the driver's seat in the SL. I keep the Version 1.0 in my tool bag.

I thought you planned to sell one or two sometime ago, or you wanted to sell the iCarsoft, didn't realized you still have it and haven't sold it yet because that was quite a long time ago.

Several years ago I did a 23andMe DNA test. From analysis of my DNA, I discovered I have the "hoarder gene" (or something like that). I have a hard time getting rid of stuff. It's genetic. Can't help it. That's my story and I'm sticking to it.

(FWIW, I did sell an older Autel MaxiDAS scanner. Wasn't too painful.)