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I like his video because its full of good information and we do not need to do our own minor interior teardown to learn
I really like his ThinkTool Pro topology feature, my Autel MS906BT does not have it, the Xentry passthru has it..... but seems his ThinkTool Pro is better with the ACTUAL topology than Xentry ... kinda shame on you MB !!
I hope you guys watch the video and slowly, to absorb it.
I also attached W211 CAN BUS information doc, its a good to read.
Learning about our car is best done when car is NOT WITH AN ISSUE, this way we take our own sweet time and absorb more information.
My number 1 fear of CAN BUS is, the ability of 1 bad module's CAN BUS ( under the right circumstances ) , taking down many other modules along with it. IF the indrectly effected modules are Gateways, damn... more nightmare.
I seen such-is-the case troubleshooting videos, but not on Mercedes, mainly on other European cars. Its the same, 1 drop of black ink, spoils the whole glass of milk... so to speak.
Gateways does not need to be called Gateway like N93 Chassis Gateway, example : Front SAM N10/1 is a Gateway by design and function.
Anytime more than 1 CAN BUS type/lane meet at a module, its like a Gateway already. May not be a full blown translator type Gateway, but at least the said module can help to report what's happening with other module/s.
MB WIS/EPC wiring diaghram is the best in terms of correct* data ( *most of the time ), but it is not the easiest to use , in fact searching within WIS/EPC for a diaghram using product name/description
can be an art in itself... results can be 100 to 300s of docs to search thru.
Below is Xentry topology for my car, which I have corrected/added to show the correct modules available and what CAN BUS-es goes to where.
01. N93 does not connect to CAN D ( Diagnostic CAN ) and also does not connect to CAN B ( Interior CAN ), so those 2 mistakes can confuse Xentry user/s. I cross X in yellow for the 2 mistakes.
02. I don’t understand how the most important module, which is the engine computer N3/10 is not shown on the Topology ?
03. N10/1 Front SAM connects to CAN B, D, E1 and E2, as to why Xentry only shows it being connected to CAN B is a very big WTF
================================
Topology shows the sharing of a particular CAN BUS lane, lets use a CAN B which has the most modules in my car.
However, unless you use the electric diag of the said CAN BUS lane, you will never know how are the actual wires routing and connections are made.
So Topo is good to start pointing direction where the fault region probably is, the wiring diag is still required to do the actual physical troubleshooting.
So you thought you need to find CAN B in WIS/EPC and do a search, alas......... CAN B is not a good search word. You must first know their duty or region served.
You must begin with this doc : GF00.19-P-0001FLM Overall network (GVN) function ( Model 212 as of 2014)
And then make a note like below : ( based on my car )
CAN BUS TWISTED WIRE PAIRS COLORS - QUICK SUMMARY
CAN A , Telematics CAN BUS. Twisted pair wire cable colors are : Black-White & Black 0.35mm
CAN B , Interior CAN. Twisted pair wire cable colors are : Brown-Red & Brown 0.35mm
CAN C, Drive train CAN. Twisted pair wire cable colors are : Blue-White & Blue 0.35mm
CAN D, Diagnostic CAN BUS or known as OBD. Twisted pair wire cable colors are : Green-White & Green 0.35mm
CAN E1 or simply CAN E, known as Chassis CAN 1. Twisted pair wire cable colors are : Green-White & Green 0.35mm
CAN E2 , Chassis CAN 2. Twisted pair wire cable colors are : Yellow-White & Yellow 0.35mm The wire sizes and colors you need to access wiring Diag.
I suggest you guys make the excel table like below, it will be visually easier than using a big size paper print wiring Diag.
Based on : RWD RHD E400, Model Year 2014. W212.065, engine M276.820 3.0 Turbo. VIN : WDD2120656L037906
Source of above information is : pe00.19-p-2185-97daa Wiring diagram of interior CAN. Model 212 Potential distributor X30/32, sheet 1 pe00.19-p-2185-97dab Wiring diagram of interior CAN. Model 212 Potential distributor X30/33, sheet 2
Modules not found in my car were removed for easy view.
Below is CAN B Z37/?? splice shown in wiring Diag
Another example for CAN E1, CHASSIS CAN 1
I tried visualizing the actual wiring using sketch below.
PE00.19-p-2195-97dac ,Wiring diagram of chassis CAN. Model 212 as of model year 2014. Potential distributor X30/30, sheet 1 PE00.19-p-2195-97dad ,Wiring diagram of chassis CAN. Model 212 as of model year 2014. Potential distributor X30/30, sheet 2
N93 or N93/7 is the same. However Xentry and Autel call it N93. WIS call it N93/7. In the Overall network (GVN) function document, it is written as N93/7
B24/15is Yaw rate, lateral and longtitudinal acceleration sensor. As per Xentry I do not have it.
N110 is the Weight sensing system (WSS) control unit (with CODE U10) (Front passenger seat with weight sensing). This is using LIN.
.
Based on : RWD RHD E400, Model Year 2014. W212.065, engine M276.820 3.0 Turbo. VIN : WDD2120656L037906
pe00.19-p-2195-97dae , Wiring diagram of chassis CAN. Model 212 as of model year 2014. Potential distributor X30/26
For headlights pe54.21-p-2106-97dab , Wiring Diag of Front SAM *** N10/1. Model 212 sheet 2. pe82.10-p-2000-97dac and dad , Wiring Diag of exterior lights *** Code 641/642 Left and Right side , E1/* and E2/* [ asterik ** is not because it is sensored, its my wild card for shortening description ]
SPECIAL NOTES :
Yes, the Left and Right Headlights are not using X30/26 distibutor., it is connected to N10/1 front SAM. E1/* and E2/* are headlights designations for MB’s. I have option 641 Dynamic LED or better known as ILS.
NOTE : When using N10/1 Front SAM diagram or Code 641/2 Dynamic LED diagram , please take note that CAN E2 at some pins are still called CAN G.
W212 up to 28th Feb 2013 uses CAN G designation and there was no CAN E2 yet.
W212 starting 1st March 2013 uses CAN E2 designation and gone is the CAN G.
To those with the same pariah engine as mine M276.820 ( 3.0 Turbo ), pay extra care when using MB WIS/EPC.
Before the 3.0 turbo existed, all document writers relating to M276 3.5L and written simply as M276 .... they never imagined there will be a M276.8
So there are times a designation of M276 will be suitable for us M276.8 owners too, sometime is not. Well its just a bad luck of owning a pariah engine model.
I dont know if its becase of M276.8 pecualiarity, but often in MB WIS/EPC when we are using its automatic link feature ( clicking a blue doc number ) between different documents numbers,
I often landed to some other engines and NOT my engine type. So please look at the title properly.
I will compile/collect and upload 2009-2013 before facelit and the after facelift CAN BUS related docs for you guys, to make a special note book ahead of any CAN BUS trouble, or for the sake or learning..whatever rocks your boat.
Last edited by S-Prihadi; 03-15-2022 at 10:21 AM.
Reason: typo
I would like to share why I would not use 3rd party wiring summary of re-drawn ones, say from like : Mitchell or ALLData.
It does look easier, but I seen both have a lot of mistakes in non CAN BUS wiring and now also with CAN BUS wiring and some can either waste your time or proved costly $$ in mistake if any damage may occur.
I give the example below :
Above LEFT SIDE showed N10/1 Front SAM drawn by Mitchell. The brown marked connection has no ID, but the pin number being 3 and 5 it would mean that is 11C connector as per MB WIS on the RIGHT SIDE.
The wire colors are correct, the CAN E1 channel is also correct.
Mitchell drawn connector 7i with pin 8 & 9 marked in red is all correct at both ends of the connection.
The mistake Mitchell made is shown above. Only N80 is correct. A1 Instrument cluster is mistakenly connected.
N2/10 SRS and N73 are both neglected and not connected.
I crossed X in grey between N2/10 to N73 of Mitchell's line, these not suppose to be connected in that manner. Z37/6z1 and Z37/7z1 is a STAR connection serving N80, N2/10 and N73.
Due to Z37/6z1 and Z37/7z1 splice is why I made the excel table, and this seems where Mitchell made their mistake
The excel table I made is so much easier to use for wiring run visualizer. Easy means less mistake.
Attached the Mitchell zip files, inside is the CAN BUS E1 of high resolution images for the Sherlock Holmes in you guys
I bought entire data of E400 of year 2015 from Mitchell, hoping their summary of re-drawn wiring Diag would save me time vs MB WIS. It ended being useless, due to mistakes in it.
Year 2015 is the time USA get E400 3.0 Turbo . Anywhow N10/1 and X30/30 wiring Diag I use is good for 2014 or newer.
thank you for this big load of interesting info. Now you can stop saying your "IT skills no-good"
As you point out: WIS searches provides information overload that's filtered one document at the time...
My big take-home is CAN Colors! It makes it eaisier to identify what bus we're looking at in a wiring loom:
CAN A : Black-White & Black CAN B : Brown-Red & Brown CAN C : Blue-White & Blue - Are all VIP's!! CAN D : Green-White & Green CAN E1 : Green-White & Green CAN E2 : Yellow-White & Yellow
Network topology
These diagrams tel a great story about all interconnections.
Thank you Surya for consistently shining the light on really hot topics out of mainstream!
Last edited by CaliBenzDriver; 03-15-2022 at 02:29 PM.
Since I may not see or experience CAN BUS issue in a long time ( I hope no issue ) , like my N10/1 front SAM documentation, I made a CAN BUS guide book to guide me in the future.
I am quite forgetful nowadays for small details. I also hate using MB WIS, it is so Un-Google like in its search function aka NOT FRIENDLY.
Not being able to copy and paste a text from MB WIS interface to my own Windows 7 NotePad or WORD... is a real pain in the azz and waste of time too,
hence documents title in XPS from WIS print out, I made them fast n easy ones ... LOL
Attached my CAN BUS Guide Book if any E400 owners may find handy.
Anywhow, all Sedan W212 shares almost identical CAN BUS wiring if not identical channel/duty allocations for the modules anyway.
I know you been poking more interior wiring in your car than me, by miles.
Is it true that the CAN BUS block is all the same, I mean there is no different keys/groove to make sure slot ID is maintained for the incoming device/s CAN BUS male connector....right ?
The X30/30 Diag shows slot numbers, I am wondering if the MB factory wiring man follows the slot number accurately when installing devices.
Its no fun seeing 6-10 CAN BUS male connectors of the same one, and when we want to trace its device/s , the slots number used is wrong
Distribution points:
these brakeway distribution nodes are used to troubleshoot shorted or distorded/noisy members.
You scope your signals while disconnecting CAN Member until you figure which is your trouble maker.
This is used by colision repairs gurus to spot smahed modules shorting the bus or missing termination resistors... type of troubleshooting game!
Performance bugs:
Modern logical functions are distributed throughout the network, across multiple controllers.
The timely flow of reliable data is critical for some type of sensitive operations (CAN-C, E) more than others (CAN-D) ans somewhat sensitive for CAN-B.
The software layer is built with a varying degree of sofistication by the suppliers in charge of adapting/testing their code to always changing environment specifications. You can expect a peripheral module (Lear) not to have expensive software the Bosch, Siemens, Conti can produce.
A lot of bugs are created by mismatched specs... hence updates sometimes help or further hurt an issue.
The hard part in electronics and software is to find ways to test what you can't see with relevant functional test cases. Troubleshooting these systems is based on known expectations. Finding good solutions is wizardry. Field users have very little control over buggy software features.
Quickly troubleshooting the performance of a system that's working poorly should be a center focus of leading German OEM's. The long list of DTC faults point to thousands of known error conditions yet for un-handled errors... goood luck up the creek!
Parts-hanging techs want part numbers to replace so they can service many customers quickly. Engineering work is not an option so troubled cars become bargain buys for lack of good fixes.
Minute 6:30 shows something I been wondering about, where are the 120 ohms x 2 resistors supposedly a CAN BUS network terminating resistors should be ?
Some cars has modules with built-in 120 ohms terminating resistor.
About terminating resistor requirement in a CAN BUS system data line is explained here :
I have ordered all 5 CAN BUS distribution strip my car uses. I want to measure them and see if indeed all has 60 ohms resistor or not, because only 1 diagram shows 60 ohms resistor, the rest none.
CAN B Interior X30/32 A000 982 00 12
CAN A Telematics X30/35 A000 982 04 12
CAN E1 Chassis X30/30 A000 982 02 12
CAN E2 Chassis X30/26 A000 982 12 12
CAN C Drive Train X30/21 A005 546 10 40
They should arrive in 30 days...hopefully so
X30/32 is the only one showing the 60 ohms resistor
As to why not 120 ohms x 2 at each end of the CAN BUS data line to also get 60 ohms , and instead MB seems to choose 60 ohms single resistor at the distribution strip....... I have googled and could not find the answer.
In the end is about how clean of reflection or disturbance the CAN BUS signal is,.......is the target and it seems MB have achieved that.
I have scoped the CAN BUS of my car at CAN D and CAN E2, it is decently clean signal.
Will update about the X30-s distribution strip if they arrive and tested, which funny enough MB called it Energy Power Distributor on some cars https://www.ebay.co.uk/p/1914118117
> CAN bars:
Thank you Surya for touching that interesting topic so often overlooked
I was just dealing with that recently. I too was surprised by the 60.Ohms resistance.
.../...
> FUN: "My Idiot hour"... lol!
Recently I got puzzled my my AUX/MAIN Batts .../...
What/where/why were you doing measuring the terminating resistor value Cali ?
Share interesting investigation please.....
3 out of the 5 of the X30 blocks are available local stock, I will be getting them 3 later today...I hope.
2 is 30+ days away.
X30/21 CAN C - DriveTrain. Carbon copy baby size of X30/32
I thought the many black squares are some sort of semiconductor , well it is just a base for the male pin. Maybe this one stronger, coz it is wider and with 2 soldering zone as anchors.
Both these X30/32 and X30/21 are by TE Connectivity
Last edited by S-Prihadi; 05-31-2022 at 03:29 AM.
Reason: add corrected info
Let me clarify some basics, as starting a project with a fatal error, would bring a disastrous results.
On W212/204/207/172 and maybe more, The CGW is a installed inside the Front SAM. Is not virtual, has his own processor, CAN drivers, etc.
If you read the sticker from the Samf, you will see 2 HW numbers and of course 2 SW numbers.
The N93 is named in Xentry...CGW (Central Gateway) and this ( not like the CAN distributors) has a more complex designation.
CGW has the ability to multiplex, to bridge, to filter, etc, data stream from different CAN bus.
Here, came the second part,
Different CAN bus, means different CAN data speed (1000, 500, 250, 125kb/s), different speed - different frequency, different frequency - different impedance, ....different measuring of terminating resistor.
Every car is different, so some modules can be present or not. Usually, the terminating resistor is present always in CGW part and in one of the module, at each CAN bus.
2X60 or 2X120, is mandatory on the data bus, for the CAN transceiver inside every module to "lock" or to "tune" the right frequency of the CAN transmission.
So,
1 - From OBD, CAN D goes directly to N93. And nowhere else. This is used by the diag system to make requests for the CGW. The CGW will "broadcast" those requests over each CAN bus to any other module. In reverse order, the answers will came back to the diag system, on the path.
2 - N93 is the "Central" gateway, but on MB, you will find several Gateways more...like the Chassis Gateway and of course the Engine ECU ( this is gateway for ISM, TCU, SCR, etc).
3 - Errors in Xentry, WIS, etc...are present, but in like 1% of cases. This statement is based on my 25 years of trained technician....
If you can accept all that ( cumulative...), I can help as much as possible!
Where have you been all this time..... this is really good, finally someone who has the proper background chimes in and teach us the DIY-ers.
Trigital wrote : On W212/204/207/172 and maybe more, The CGW is a installed inside the Front SAM. Is not virtual, has his own processor, CAN drivers, etc.
I know Front SAM has gateway capability as described in component description gf54.21-p-6070fl ,
specific to N93 Central-GW , I have assumed it is truly another stand alone extra GateWay not within the Front SAM , like how N93/7 Chassis-GW is ... LOL.
This is really good you chime in. I know you work professionally & for profit, but I hope you can be a "visiting" educator too..
Now some questions if I may... Trigital wrote :
Different CAN bus, means different CAN data speed (1000, 500, 250, 125kb/s), different speed - different frequency, different frequency - different impedance, ....different measuring of terminating resistor.
What Ohms values are we supposed to read for CAN C Drive Train CAN between canH & canL, if all power removed from modules but all modules connected and none are defective ?
In my case, the CAN C on X30/21 distributor has :
- N3/10 Engine Computer
- N118 Fuel Pump Control unit
-Y3/8n4 tranny
- A80 ISM-Direct Select
I don't have yet any project per se, but I am trying to sniff Low Beam and High Beam command for my 641 ILS LED on the CAN E2. I want to add extra driving light which so happen can do Low and High Beam too.
This is because 3rd party ready-to-use High/Low Beam sniffer module with relay output, none of them ( 3 brands ) replied to my emails and their units can work with non-facelift W212, so they claimed.
I emailed them all twice. I don't understand why no reply, they can simply tell me No-Can't-Do or whatever the actual status is.
Repairs, is about simple procedure. To do repairs is enough to follow some simple steps and is not necessary to have deep understanding of MB engineering.
In a busy workshop, when there is CAN communication problems, beside checking fuses, cables, connectors, with a simple voltmeter, you can measure each CAN rail compared with the Ground .
~ 2,40V and 2,60 ( total is always 5 ) this is OK0 or 12, or 8 however....means something is wrong.
Remove CAN connectors from distributor, one by one, till CAN is alive again ....simple The one that remains not connected, the one who kills the network, is the defective one.
If all this is not effective, than an oscilloscope, some more complicated measurements should be done....but if you use Xentry, than maybe in 95% is your chance to repair your car without much effort.
Repairs, is about simple procedure. To do repairs is enough to follow some simple steps and is not necessary to have deep understanding of MB engineering.
That is exactly the opposite of my intention
I want to avoid repairs, touch wood, I don't enjoy handling wires so small and cramped working space in a W212.... if I can.
What I enjoy is understanding my car engineering as a time killing proses and keep me busy doing something to keep my brain working.
Again, touch wood.... in the event troublecomes, I am not too fearful to tackle the issue myself.
However, I am a strong believer of peventive maintenance, but as you know, electronicss are rather unpredictable when and if they want to go kapoot.
My Xentry is a naughty passthru using Tatrix Openport.My passthu software type can only read and nothing else, good enough for now though.
I really enjoy this W212 as a laboratory. I last physically mess with my cars was 20+ years ago, but they weren't complicated back then...majority mechanicals and very analog, unlike a W212.
My xentry passthru is offline use, I got it from youtube
I am sure if I use MB official channel and the correct/proper passthru device , it will be as good as you described.
I am IT stupid, my apology....
Since you know so much about the CAN BUS, please share some pointers. Thank you
I want to correct this thread and my notes, to reflect the important information on N93 CGW being physically inside Front SAM N10/1 as you explained.
I want to know, is Xentry Topo so full of errors ? or perhaps some explanation from you who has 25 years experience with early to latest MB diag software can shed some light.
Why A1 Instrument Cluster wiring diag shows two CAN channels while Xentry Topo only shows A1 having 1 ?
I personally never yet and probably will never.......... teardown A1 Instrument cluster to see if indeed as per wiring diaghram there are CAN B and CAN E2 connected to A1.
I assume wiring diagram is more trustworthy ...correct ? If so, can I simply deem Xentry topo as useless and never look at it or it can actually come handy somehow ?, specific topo feature only.
03-15-2022, 08:45 AM
, well it is just a base for the male pin. Maybe this one stronger, coz it is wider and with 2 soldering zone as anchors.
, thank you a million.
, like how N93/7 Chassis-GW is ... LOL.
