Electrics: 70: Diag issues - 1/2 of the car will not communicate

[Foxik]

Hello,

I will start with a little disclaimer - it is my first post, not just here, but on forums in general. I hope that I did everything right (right category etc.), if not, please let me know - I will try to fix it.
+ Pardon my imperfect English.

Now to the problem itself:

"Introduction":
In my country, we have car state inspections. My V70 is due for one.
My SRS light is on, and, because of my stupidity doing brakes, the ABS light is on as well, thus I have a great start for state inspection...
I do not want to take out DIM lights, I want to fix the issue(s).

The issue:
The first big one was to realise that V70 I (1998) is in the perfect years of 1996-1998, so OBD-II is not OBD-II, and the old Flash codes are no longer here.
Thus I bought VAG-KKL, later VAG-CAN-K cable, got myself VOL-FCR and VAG commander and tried to diagnose the DTC, and erase them.

Now the "fun part" - half of the car does not want to communicate.

Engine, immobiliser, clima-module works fine - I can speak to them, I see the live data and work with DTCs.

SRS module - I can communicate with it, after making the connection and asking for DTC I got "faulty data", live data are not readable (? instead of data).

ABS module, DIM, and few other modules are not responding.

Now "the well" where I have fallen:
I have spent about 30 hours trying to solve it, diagnose it, fix the issue.
I will write here everything I have done that I remember.

I asked on the local Facebook site for help, only answer I got was to check the solder on the pins on the ABS module.
So I did - pins were fine, I did resolder them, to be sure.
I did the same for DIM. I have seen some old fixes in DIM where the heat sink rubbed the PCB. I did checked these places with DMM and put lacker over them to be extra sure. Because the DIM works as it should (beside the com issue), I do not think it is damaged.

During my poking into these modules, I did find CAN transceiver chips and traced them to pins on the connectors. I did hooked CAN-Hi, CAN-LO vs. GND on the oscilloscope. When I was with probes behind DIM, with ABS disconnected, I did see sync pulses. When I connected it to ABS, I did see data transfer. I did usu DMM to check voltage at CAN-Hi and LOW - both are about 2,5 V. Thus this part of CAN must be fine. But it seems that DIM CAN is only connected to ABS module. I could not find any info if this is OK, or not.

I did put probes and DMM at OBD-II port and it was silent - no CAN signal.
From what I could find on the internet it goes straight to CEM - I do not know, if there is some active safety decoupling of the OBD-II port vs. the car, or some transceiver/signal converter.
CEM is hidden so well that I can´t reach it.
So I did the risky thing and connected CAN behind DIM with OBD-II CAN (bypass CEM). I can now see CAN voltage at the port but the com issue is still present - nothing has changed in any way.

I did find that a typical CAN has 2 terminating resistors on both ends. I tried to measure them, but I have not measured any ohms between CAN lines at ABS and OBD-II. Thus I assumed this car (maybe cars in general) does not have any. Does cars, especially V70 I have CAN line resistors? If so, where are they?

I did check many things visually, but everything seems to be OK.

Internet is silent about similar issues, Chat GTP had gave a lot of info about CAN, K-Line and OBD-II coms, but I still don´t know what should I do next.

I could not find a definitive answer if Vida DICE will work on this car. It is pricy and and do not want to buy it just to try it. + I personally thing that I will not work.


"The question":

So, is here anybody, who can point me in the right direction? I need my car on the road, and these issues taken care of.
It´s sad, but You are my only hope - I do not where else to ask, or what to do next.