CaliBenzDriver

Thank you Surya for pointing out all the above 👍

This made me realize why my Reverse Cam has always been loaded with poor connection faults. It's path to Direct Selector module at column is busted. This means camera is not chatting with the busy TCU, thank God for that!


> You know how the 4x modules report having connections errors:

- How do they report being unable to talk?

- I don't think the Diagnostic CAN is connected to non-VIP peripherals.

Funny thing is Direct Select is a super simplistic reliable module. What all this mess has in commun is the SCM steering module at the transceiver.

The way this module needs to be rebooted suggest its non fatal hardware problem. Noisy power supply impacts board stability by causing timely non-random soft-crashes.

The faulty modules usually share identical birth defects from required design standards:

1. inadequately filtered DC power
2. extrimely poor GND lines
3. poorly connected circuits
4. environmentally challenged locations
5. low voltage promotes (dV/dT) surges

In contrast with world-class electronic designs.
😏

S-Prihadi

I am compiling all related WIS for Juan and/or others to start tracking his/their PARK problem...now that I am in Jakarta and in front of my PC hehehehe
Damn so much information to swallow. This will take a few hours.

In the meantime I am focusing if this is a low voltage glitch and some duration of LOST-COM being the result for a while or bad connection at CAN BUS distributor or somewhere else.



Assuming Juan list for module 02, 03 and 04 are the reporter modules themselves reporting of their own COM-ERROR, module 02 is A80 is CAN BUS C and not CAN BUS E1 like module 03 and 04 the N73 and N80.
I have to see N3/10 ECM for M276 3.5L wiring diagram to see the CAN BUS C and E1 connection.
I know on my M276 3.0 TT N3/10 engine computer, it has CAN BUS C and E1 , both into the Engine Computer. So Engine Computer acts like a gateway too... I suppose.

Will be back...........

S-Prihadi

Juan,

So, which exact DTC are issued and by which modules ?
Example N80 alone can issue a lot of communication DTC




But there are modules which has no list of its own DTC, at least for my car which should be the same as your 2014 model year I guess

juanmor40

Thank you both @S-Prihadi and @CaliBenzDriver for your help on this.

I was not as calm in the garage and caved in deleting the DTCs (before taking pictures/snapshots) when XEntry hung on me , and that is why I do not recall them exactly. However, from Surya's images for N80, I recall P17200 "The DIRECT SELECT lever has a malfunction", and one U code, but not certain if it was U119800 (ISM), or U11A300/U144200 (camera).

Last time when Surya was cleaning the ground points I recall cleaning all in the trunk (since I took all the dressing off), the passenger footwell, and the top level ones under the hood. My laziness to clean the engine/transmission straps and the driver-side footwell is rearing its head now.

I think my initial step will be to take the carpet off on both front sides and check grounds and CAN connections are clean and check for humidity. Clean ground straps under the hood. I am debating what next between the EIS solderless, or the ISM (which I would love to avoid)

Separately: if the programmers for XEntry are in any way related to the modules programmers I now understand why these cars are so unstable. XEntry hangs whenever you shake your laptop, . No kidding, I pressed the Close X for the PDF Printer, and the session became slow, unresponsive at times until I restarted XEntry. However, PDF center did not work anymore until I restarted the laptop . My fault I guess for shortcutting the programmer's expected workflow from users. These systems are behaving like Windows 3.1/95/XP, if it fails/hang --> REBOOT.

juanmor40

Thank you very much for the suggestions, I will keep them in mind (see my previous answer).. Definitely, it was not fun when it happened.

Once the labour rate hits $150+/hr, the provider better has something I cannot provide ; otherwise, I make the effort to learn it. I am not paying $2K+ unless it is 1000% certain it fixes the root cause, not the symptom.

Enjoy the trip to TAHITI. Not been there, but I have heard it is beautiful.

juanmor40

Thank you very much for the suggestions, I will keep them in mind (see my previous answer).. Definitely, it was not fun when it happened.

Once the labour rate hits $150+/hr, the provider better has something I cannot provide ; otherwise, I make the effort to learn it. I am not paying $2K+ unless it is 1000% certain it fixes the root cause, not the symptom.

Enjoy the trip to TAHITI. Not been there, but I have heard it is beautiful.

S-Prihadi

LOL...our Xentry PassThru is a naughty version, so hang once in a while is expected.
Our interface the Tactrix Openport be it clone or genuine ( I got both ), is not a J2534 certified, so perhaps hang once in a while will happen.

The most often case my naughty Xentry Passthru got hanged is when I do certain bi-directional control, but never when trying to scan for DTC.

I taped my USB cable the one going to the Tatric Openport dongle, for better contact and stable operation.

==================

Attached full WIS documents to help you understand PARK and other supporting docs when wanting to troubleshoot it
There are 3 documents explaining how PARK works, the how the why yada yada

==================

Too bad you did not screen capture the real DTC, because others often reported no DTC when having this PARK issue, but they may not all have Xentry, so perhaps there could be DTC hidden as stored/historic.
Those DTC can lead us to a faster fault findings.

===================

The common denominator among the supposedly 4 modules reporting the supposedly COM-ISSUE , is for now Engine Computer.
Untill those 4 DTC comes back again, as you have planned : work on cleaning ECM grounding and its main 96 + 56 pins connectors,
main negative ground cable under the car body which run to starter.... which WIS never even catalog it ,
and
CAN BUS distributor block and its ground.


This is the CAN BUS C at Engine Computer. The F connector ( 56 pin) , pin 42 and 55 to X30/21 distributor. Also CAN BUS E1 at F connector pin 41 and 54 to X30/30 distributor.





X30/21 CAN BUS C distributor block








---------------------------------

SHEET 2


So summary is below for your car and is 100% the same as my car.

ADD : Slot 4 - N89 Tranny Aux Oil pump Dang, I am blind


=========

You then do the same for CAN E1, delete what is not for your car.


For my car, the CAN E1 is as below


Lets assume your CAN E1 is the same as mine in relation to N80 and N73. These N80 and N73 is actually via N93 CGW (central gateway) inside the Front SAM N10/1 and not connected directly to X30/30 distributor block.

If say we suspect bad connection at Engine Computer N3/10 connector F ( 56 pin ) for the CAN BUS C and E1, it would likely N118 Fuel Pump Controller will also report communication issue as it is within the CAN BUS C.
Well if the fault duration too short, maybe N118 may not register any DTC. Also, N118 does not have built in DTC to report Communication problem , the Uxxxxx. It has only Pxxxx type DTCs.


This is why the DTC message issued by which module/s and what they described as the fault is very important to have to ease troubleshooting.
We must visualize the data flow : where to where via what. This is assuming bad connection at somewhere within the CAN BUS C and E1 network.

If we assume low voltage event, we then must suspect fuses and power cables supplying power to those supposedly 4 modules.

Enjoy the looooonnnnngggg reading

S-Prihadi

NOTE : Your CAN E1 is the same as mine in relation to N80 and N73. These N80 and N73 is actually via N93 CGW (central gateway) inside the Front SAM N10/1 and not connected directly to X30/30 distributor block.

Below wiring diagram. This is why I said : These N80 and N73 is actually via N93 CGW (central gateway) inside the Front SAM N10/1 and not connected directly to X30/30 distributor block

Above, is the 2nd CAN BUS E1 connection to Front SAM N10/1. I then assume this one goes to N93 CGW processor.


Below is the 1st CAN BUS E1 connection to Front SAM N10/1. I then assume this is for Front SAM's processor.




I honestly do not know which CAN BUS goes to N10/1 Front SAM for Front SAM own processor and which goes to N93 CGW processor which is also located in Front SAM.
But I have to indicate that they are infact 2 of CAN BUS E1 connections to Front SAM, so I name them differently

It is unfortunate that above document ( attached ) : gf5421p6070fl Component description for front SAM control unit with fuse and relay module
does not name the Central Gateway as N93



In Xentry, it will show N93 Central Gateway and also N10/1 Front SAM as separate modules, but one may mistaken N93 CentralGateway as N93/7 Chassis gateway control unit (with CODE 23P (Driving assistance package Plus))
See 1A N10/1 Front SAM and 1B N93 Central Gateway, below :

juanmor40

Thank you very very much for all the information Surya, . I appreciate your time collecting, and summarizing it. Let me digest it.

===> Coming back from lunch, it did it again .

Let me read your previous responses before I hook up XEntry later this afternoon. I want to capture as much information as possible. Long evening ahead I guess.

S-Prihadi

A quick test and prevention.
If you are now using the PUSH BUTTON start aka wireless to key FOB, remove it and use the key fob manual insert, like I do.

We first eliminate another possible weak link, just in case your PARK issue could be from short duration loss of Drive Authorization from Key FOB.
https://mbworld.org/forums/e-class-w...ml#post8708639

juanmor40

Today I am glad mine is not KeylessGo (though I would have liked to). W166 is KeylessGo-PushStart (w push button stored in the glove compartment ), and the W211 is KeylessGo with push on the console shifter (pre-push button on the steering column).

Currently going over all the documentation: first sorting out the ground points, and marking those I already did, then studying the diagrams after I collect the latest DTCs.

Going over XEntry yesterday, I noticed some components are associated with my VIN; however, XEntry indicates they are NOT personalized. Have you noticed that on yours? Let me take a snapshot and share it later.

CaliBenzDriver

This thread title is about "the car throughs itself into P at low speed". Here we have a related fault "the Direct-Selector shifter doesn't work" - Two distinct issues but actually related.

We've seen how everythings get overwhelming pretty quickly because diagrams encompass entire production options with updates CAN E split > E1+E2. CGW getting merged into F-SAM.

It's an excellent exercise to understand how things work. It helps understand how they disgunction when they don't work.

What happened to Juan's W212 is the Direct-Select stopped controlling the gearbox shifter ISM while the ECU had no problem shifting to P, N. Meaning the path to ISM was proven functional... half the battle.
The broken path was from shifter to ECU. This is when I come forward to drop a nugget on our work bench....
There is something particular not scribed in the schematics we learned to rely on


misleading system diagramRead this block diagram to observe how things are connected.


cheapo basic shifter control

Shifter is a cheap dumbo circuit and SCM stack of PCB's is the local Lord hosting other peripherals that speak through it's I/F circuitry.


Not Splitting hair:

1. bad SCM module,
2. bad GND supply,
3. both combination

Unless we scope the frames that cause havoc to the timely work of VIP modules, we are not going to know exactly the cause of soft-crashes SCM Coms. I found easy to bring Benz electronics quality up to basic Japanese grade.


Plucking the Lemons out :
The shortcut I have selected is to fix both sources of engineered troubles. Unexpectedly this has payed off with ECU-TCU working seamless shifts like a machine gun. Both ECU and TCU now work totally awesome unlike when SCM floods ECU with retransmits.

Golden Easter Eggs...:
The engineered defects Benz carefully bakes for decades are easily managed and removed in other iteration of chassis, markets variant.

This body of knowledge by team Surya-Cali-Juan will help fund a rewarding getaway trip for many forum participants.
Enjoy.

juanmor40

Update: XEntry data via snapshot. Bear with me here

Results from quick test 5 errors: 1 hard Fault, 2 soft Faults, and 2 information

Electrical Power Steering details


Backup Camera detailed information


Results after Xentry if I wanted to test the module

NOTE: suggestions toward electric wiring quality, either contacts or corrosion , they are very much aware of the problems

Steering column module:




Intelligent Servo Module/Shift Module:







I will update this post later.. Just uploaded the collected data.

S-Prihadi

.

Aha, more homework. EPS now as CURRENT FAULT. I think attack this problem first.




Juan, you need to clean the EPS connector. I worry you have oil seepage from VVT window like I on mine, but on mine oil did not enter the connector...yet.

Look at the green + white baby wires, those are the CAN E2.



The EPS message is unique, but overall , I believe it still points to LOST-COM from EPS itself.
U40100 EPS saying ECM is sending implausible data, but E010100 EPS is saying it can't communicate with Tranny.
If say intermittent CAN BUS issue is with EPS, it probably did not catch the message from ECM and unable to catch message from Tranny too.
I believe all these modules always send to each other at pre-determined time messages of OK-OK-OK-OK of similar status information and not only transmit when needed.

So CAN BUS chip in EPS loss of hearing is the same as loss of speech aka LOST-COM. As to how engineers define or describe the DTC I do not trust 100% word for word.
Example, if we read U40100 Implausible Data Received from combustion engine ( N3/10 ECM ) ... one would think the ECM is the one going cuckoo , what if EPS went DEAF for a while is actually what happened ?


EPS gets power from F32 Prefuse fuse of 80 amps and the number is F157 for start-stop car B03 option, 80 amps is due to the high power EPS uses which can be easy 50-60 amps at peak.
EPS ground cable is also very big, clean it up.

I am attaching EPS + F32 documents for you.

EPS uses CAN BUS E2, the same with your Reverse Camera.

Becareful when trying to detail out all E2 CAN BUS interconnection via wiring diagram of X30/26, because for facelift version car with Dynamic LED ILS, the Front SAM N10/1 is still labeling CAN G for CAN E2 and you will not find E2 connection of those lights at
X30/26 CAN E2 distributor block, but it is at Front SAM N10/1.



Slot 7 is for N88 Tire Pressure Monitor Control unit if the car is so equip
Slot 8 is for B84/3 Reverse Camera or N148 360 degree camera if the car is so equip



====================

To map out any CAN BUS topo, best start with the CAN BUS Block diagram and at the same time the wiring diagram to delete and verify what module/option not in your car and
have WIS/EPC on 2nd screen for further reading of all linked wiring diagram, as this is a very confusing task. Expect some labeling error or linking error from WIS too




For my car, I have verified what modules/options I have and spotted mistake made by MB for above CAN BUS topo vs X30/26 CAN E2 wiring,
and also mistake at the X30/26 CAN E2 wiring diagram for the links. This is where my migraine usually sets in.


BELOW : If for my car and see how MB CAN BUS topo forgot to place A1 Instruments Cluster

I have re-drawn the interconnecting lines to represent actual physical CAN BUS E2 cables real time routing as per N10/1 Front SAM wiring diagram.




From X30/26 wiring, we then know that the CAN E2 wires for EPS N68 are not at the X30/26 distributor block, but at Front SAM N10/1



We then verify at N10/1 Front SAM, is X30/26 wiring correct for N68 EPS CAN E2 ?
Yes it is



You best inspect and clean + tighten the F32 prefuse block nuts. MR3 is for N68 EPS for F32 of B03 option.





Have fun troubleshooting............. for N68 EPS

S-Prihadi

Cali,

So the S16/13 DIRECT SELECT lever small PCB is the interface for these 4 functions : PARK, DRIVE, NEUTRAL and REVERSE selection....correct ?
Did you tear it down enough to see what kind of physical switches those 4 function uses ?
Dang, one can not buy the S16/13 lever stand alone without complete N80 SCM



This reminded me of how my steering wheel pedal switch interface N135 board went bad and keep dropping gear down. But I could buy N135 board stand alone.

juanmor40

@S-Prihadi thank you very much for the feedback. I do appreciate it.

1st task: Connector for ES
These are views from the top using a camera. I do not see much oil around. I could use some electric cleaner on those connections as a preventative measure anyways. The error is coming from that unit anyways.

I captured the N68, correct?



2nd task: PreFuseBox, opened and cleaned all internal connections (PITA because of the tight space to sand). They were mostly clean anyways, but since I already opened I cleaned a bit anyways and used Deoxite

PreFuseBox_Open

MR32 Post w.o cable

PreFuseBox external posts most right

PreFuseBox external posts most left . They were not as good as internal posts though. Cleaned, deoxite and put back together.

3rd task: Engine Bay Ground Points cleaning
W2 done: just below the coolant reservoir and worth doing.
W10 done: near the battery. I did it again anyways
W11 pending: is it below the intake, or just behind the air filter? Need to check if the aspirated engine has two W11, or just one.
W2/1 and W3/1 are pending; they are behind the right wheel cover, correct? Those are really exposed to the elements
W70 and W9 are pending: they are also behind the left wheel cover, correct?
W16/6: I did not see it, and if it is there means the battery is out again,

Weekend plan: both wheel cover off, right side, starter, and left side.

CaliBenzDriver

You missed an opportunity to practice soldering the day you purchased N135. It would have come handy now for graduate level $$$$ modules 😁

I think gear selector has only 3 switches:

1. push up: R
2. push down: D
3. push in: P

N is implemented by software filtering input request (to never shift into R or P while speeding in D)

I did not further disassemble the selector, it's been only good for me.


N80 SCM 🤪

What is the exact list of CAN-E1 Modules...
I think this is closely related to list of faults, true?

This CAN-E1 is prime candidate to scope for amazing views of what's going down.


​​​​​​+++++++++++++
EPS is somewhat likely okay... LoL
(TSB's are littered with EPS issues)

It only wants to find out what the steering wheel is doing: centered straight or turned L/R.
Without that car drives over a barrel instead of being planted straight by EPS at highway speeds.
FYI: My EPS got dealer recalled for a rebuilt unit nearly new at 10kMi.

CaliBenzDriver

How could we all forget the STEERING rack has an active fault until the engine gets running to power it.

> Rescan EPS faults with ENG =ON __✔️

Check to confirm that particular EPS error is gone, Your EPS is now declared working within expectations.

My satisfaction rating of EPS :
clever trustworthy device, so is ESP as well. So far they seem off limits for ownership-rash.
🤞

juanmor40

Thank you . Saved me something to worry about.

Here is the updated XEntry snapshots, very similar


Summary diagnostics



Backup camera errors



Backup camera error 1 suggestion



Backup camera error 2 suggestion



Steering Column error



Steering column error suggestions



Transmission module errors. Interesting the reported instance at 27K miles. The vehicle had never any issues, and that would have been circa 2017 . The first section indicates those two instances were always when ready to reverse (something to keep in mind later)

I plan to continue cleaning the grounds in the engine bay, then the interior and check the CAN blocks under the carpets

CaliBenzDriver

Let's loose a few bits of MB chaos by compiling field data in the Steering chapter:

1- The EPS rack acts like "nervous Nelly" crying wolf when engine zero rpm is obviously not running. Rack reports "broken COMs": duh!
Indeed rack is not yet fully powered - This is not really a significant problem, only poor self-diagnosis.


2- Chassis CAN-E has evolved into 2 split networks so chassis modules can have chaos on E1 with E2 mostly pristine.
- This costly design change got pushed through, I guess practical reasons!
- Priceless steering rack campaigns for EPS needing replacement.
- Designers did a very proactive job with prompt "service campaign" to keep all that steering jazz underwrap.


3- It's underwhelming to realize how the expensive steering disfunctions got REFINED CAN-E1+E2 instead of eliminated.
It got morphed into the complexity we are dealing with. A hard fault with vague messages steming from a crafted failure.


4- Luckily the mature steering design is built with sufficient redondancy that steering can disfunction and keep working safely in a degraded mode.
Very few vehicle drivers are going to ignore nagging from brakes and steering controls the way HVAC, wipers and oil leaks can be overlooked.
The modern Power Steering system is built as a profit center with poor connections to require premature repairs.


Why not allow premium cars to be reliable??

CaliBenzDriver

You're are pretty much off the hook with standard EPS fault but I think your car may have a case of yoyo... tranny reporting a fault while driving with 12.0V raised my eyebrows:


dismal VGS Voltage while driving

You know.... if alternator was normally powering the car, it should operate with a voltage between [12.6V <>14.9] at all time and more so while actively driving.

Go ahead and set your IC to display battery sensor data while driving. You need to know what's happening with your car voltage control. Hopefully GND campaign will bring in joy like when recently Ivan fixed a painted GND strap on a Hyundai car: built like a Benz.

S-Prihadi

Not on my car. However when I scan the car, I always use power supply set at 13.2 volt at the device and car will use approx 12-15 amps and battery voltage at battery post will be 13V at best.
I don't want to overcharge my battery, I only want power maintainer and charging into the battery at no more than positive 1-2 amps at best. Sometimes it may even show -1amp and battery voltage 12.7V,
depending what bidirectional command I do.

Avoid using scanner and not having a battery maintainer, low voltage do wonderful confusing things to the modules.


ADD======
That funny circa 2017 mileage DTC appearing, I too have seen such a glitch but approx 2 weeks old and not as old as few years by mileage.
Its like the module has amnesia and just recovered
To this day I do not know what actually happened..... but removing battery and re connecting it, sometime can produce weird STORED DTC.

S-Prihadi

Juan,

I been reading more......

==========
Two important questions ;
01. Is your car a B03 Start Stop with 12 Ah battery at the trunk ?
02. If your car is B03 option, was the Start Stop active when all these troubles happen ?

=========

The ISM A80 network arrangement seems so in-direct. I wonder why.

ISM A80 uses CAN C.
VGS Y3/8n4 uses CAN C
Steering column N80 where the DIrect Select Lever is at, uses CAN 1 ( E1 )

At post 57 I mentioned : The common denominator among the supposedly 4 modules reporting the supposedly COM-ISSUE , is for now Engine Computer.




So it is true that the Engine Computer N3/10 is seems, is the gateway for CAN C and CAN E1.



However, I kind of worried looking at the power source for A80 ISM. It is the rear SAM N2/10. So, long wire run involved.


The power flow for A80 ISM as follows :

Based on B03 start stop option
At F32, From fuse F159 Circuit 30 ( 30 meaning no K2 relay involved ) to Rear SAM , via IM1 stud of F32 and wire size of 25mm to an intermediate junction box called X4/37 and then
to K114 ( the 12 Ah battery parallel relay ) and not direct to Rear SAM.
From K114 of the same stud, another smaller 10mm cable and fuse F97 hidden inside a black heat-shrink tube are used to send power to Rear SAM to connector 2V.
This damn connector 2V you will never find at rear SAM because the label is not 2V, but the actual label is KL30.
From Rear SAM N2/10 , power +12V via fuse 88 of 15 amps is then sent to A80 ISM. Dang what a long journey.











You need to make sure K114 connection is clean and tight. No need to teardown Rear SAM to access 2V/KL30 connector I guess....unless you want to clean them as I and Cali did.

Remember 30 or circuit 30 is direct battery, so to speak.
Circuit 30g or 30g is always via K2 relay at F32.

A relay when worn out can produce low voltage or intermittent low voltage
.

S-Prihadi

If you are asking where is intermediate cable junction box X4/37 from F32 to K114 at the trunk, I can show you my RHD car version and it would be similar to your LHD version.
I do not know if non B03 option uses the same junction box or not ? I supposed they do use the same, because Circuit 30 has to be made available at rear SAM anyway.


If LHD car






For my RHD car

S-Prihadi

Juan,

If I may suggest, while your are now playing around with F32 prefuse box..............

Have you ever tested your alternator AC ripple and voltage drop at K2 relay ?
Alternator AC ripple can interfere with CAN BUS signal.
K2 relay is a relay after all and could have its contact pint weakened overtime from use.

Alternator AC Ripple.
If you do not have a simple 2 channel scope , I am sure you have a true RMS voltmeter. You can use its AC voltage to read AC ripple from the alternator. I have checked mine sometime ago as part of
preventive maintenance or inspection.

Our alternator basically is a 3 phase AC output and smoothed/rectified using diodes to produce DC, but it still has some AC ripple nevertheless.
If a mere 1 of the diode is not healthy, AC ripple will increase and sometimes voltage too.



My hand notes in blue :
1 is the voltage regulator
2 is the carbon brushes set
3 are the three coil winding of the 3 phase alternator
4 are the 6 diodes , 2 for each phase

Google how to test alternator AC ripple with a DMM.
https://www.motor.com/magazine-summa...ripple-effect/
http://www.pvv.org/~syljua/merc/TooSeptST07.pdf

HVAC full power and headlight at high beam would be a good load.

============

K2 relay voltage drop.
Engine OFF but key in ready to crank & Headlight at high beam & hvac blower at max , this would be a good enough load of approx 30+ amps
DC millivolts setting, reading jumper post to IG1 stud.