mb_texas

Does the order/location of the individual connections matter on the CAN bus distribution hub? If so, what would be the best way to figure out which cable goes to what system? this picture is not X30/17 but is a visual hint of what I'm talking about.




If location does matter, on the diagram contained in the PDF, note the order of connectors, 1, 3,5, 6,7,8,9,10,11,2

Assuming left-to right ordering, is the second from the left position #3 or #2 ?

DavidCA

No, it does not make a difference as they are all parallel with each other.
However as you see on the schematic they are numbered and assembled that way when the car is built.

There are two signals on this CAN bus, CAN Low (the brown wires) and CAN High (brown wire with a red or black tracer.)
The black / black-white wires connect to another distribution block somewhere else in the car.

The second from the left position is #2 but all are functionally interchangeable.

mb_texas

Thank you very much!

KLinNBC

MB_Texas, where is this CAN bus? Or more to the point, the CAN bus distribution block that you are referencing? I need to find it, I'm into the passenger side footwell, carpet and cover off, subwoofer enclosure out and can't see anything that looks right.

g0rsq

The main one is in the fusebox area behind driver (UK spec) seat.

KLinNBC

As it's developed I need to find X30/18 which I believe is the sole CAN C block, all the others are CAN B. And I believe that X30/18 is in the left side door sill. Can anyone confirm or provide better info?

bbirdwell

See photos below.

KLinNBC

Awesome, thanks very much!

g0rsq

Just a quick note, removing the CANBUS plugs can be quite confusing and challenging.

Here are two pictures I took showing how they come out.

To remove the locking cover, press in the two tabs, one at each end, and the whole cover (with tabs) slides sideways from the main plug.

Then use a small screwdriver press in tab of individual plug to enable it to be released.

KLinNBC

Thanks so much! I doubt I would have figured this on my own, you saved a bunch of time, frustration and blood pressure points.

elMacko

Junior, I wonder why are you accessing the CAN C..? Perhaps you are having the same issues I am having..! A DTC tells me about a miscommunication issue that points to one of the subsystems connected to CAN C.

I have not have the time to dig into that but suspect it may be a contact issue due to corrosion on one of the terminals..! Please let me know your findings and results!

Thanks,

KLinNBC

I am installing a LoMo M1 lowering module.

MR.AMG.

Hi please help i have a no crank no start issue my scanner has led me to this connector x30/18 when I got to it the connector next to is was wet and corroded i have sorted that but still have the same issue? I am getting all negative signals on x30/18

g0rsq

What do you mean 'all negative signals'?
To check this connector you will need an oscilloscope, checking each wire to ground. You should see a "square wave" or pulses on each wire when they are communicating.
All voltages are low, around 5v against ground.
If you put your multimeter on AC voltage you may be able to read an average value depending on how good the meter is, but an oscilloscope is the correct tool.
However if you have diagnostics you should see which modules are inaccessible.
If they are all inaccessible through this connector then you should be looking at EIS or diagnostics module.

MR.AMG.

I have a basic voltage tester which lights up red or green wether it's the green/white wire or green only i am only getting a negative light

MR.AMG.

Do i test these connectors with the ignition on?

bbirdwell

Both on and off. There is voltage on the CAN bus whether asleep or awake. Use a multimeter, oscilloscope, or CAN bus analyzer. The third link deals with a no crank, no start issue solved by disconnecting a bad transmission control module that was nuking the CAN bus. Once identified, the tech replaced the bad module.

https://mbworld.org/forums/e-class-w...is-repair.html

https://mbworld.org/forums/e-class-w...-part-2-a.html

https://mbworld.org/forums/w211-amg/...-no-start.html

elMacko

Birdwell, thanks for all this info......now I got deeper issues and need to start digging on the CAN modules! I really wonder why the MB techs wanted to implement such a complex electronic control system..! Perhaps they wanted the quasi-mechanic owners to go to the dealer's shop which needed to generate revenues!

MR.AMG.

Hi would you know which sam unit the x30/18 connector leads to? I had water damage on my connector i have rewired it but still have the same issue

bbirdwell

https://mbworld.org/forums/r-class-w...ml#post8930415

g0rsq

CAN C wiring diagram

MR.AMG.

After rewiring water damaged x30/18 and x30/15 connector i have these faults mainly going back to connector x30/18

g0rsq

Was the ignition turned ON when you used your diagnostics? Terminal 15 is generally the ignition ON supply.

If this is missing you will get a multitude of other faults.

MR.AMG.

Hi yes ignition was on and now the whole power is getting cut out after like 10secs I really thought repairing the wires would've solved it but seems like something else has gone on after the water damage

MR.AMG.

Hi yes ignition was on and now the whole power is getting cut out after like 10secs I really thought repairing the wires would've solved it but seems like something else has gone on after the water damage