D3 computer issues (the whole bus)

[Denisrangie]

Hi Guys
I am getting desperate and need some help from anyone who has been there before.
I did a body off to change the crossover pipe on a D3 2.7TDI (and belts and filters).
I had the system come up prior to this with "System Fault" and the screen and stereo rebooted about every 20 seconds (I ignored it).
Now I have everything saying it is faulty - transmission, EAS, Park Brake, stability, hill decent, ABS and just about every light on the dash.
My Nanocom will no longer connect as it cannot read the VIN either.
I have checked the HS and MS bus at the OBD2 plug and they both read 60 ohms resistance (correct) and both have data on them (used a 2ch scope).
I have also checked all the wiring and replaced the main battery with no luck.
I have removed and inspected the CJB (BCM) and it looks good - no water or dry joints and all the fuses in the car are good.

I have a spare D3 petrol base model (mine is a HSE with the E diff) so can swap most of the computers.
Question - If I replace the CJB and it has different options and keys - will the car accept it so I can then use the Nanocom to sort the key learning out?
I know the CCF files are mastered in the instrument cluster and backups are in the engine ECU and the CJB - will the car update the VIN and CCF data in the "New" CJB?
Is this also going to happen if I replace the other ECU's as part of my troubleshooting.
My concern with taking it to Land Rover is without them being able to connect their test book due to the data bus issue - will this cost more than the car?
It has been great for several years and I was hoping to keep it form many more as it has a lot of accessories and a bullbar with winch.
Too top it off - rego runs out in 2 days (when it rains it pours).
Can anyone give me some good troubleshooting tips.
The car runs (in limp mode on the bump stops 30km/hr)
Regards
Denisrangie (and I thought the P38 BCM was crap).

[libertyts]

Rubbish situation to be in mate, I feel for ya.

The first thing that comes to mind with everything carrying on, but still having something going over the lines is maybe its power related. You've replaced the battery, so that eliminates that. It was about off, any chance you've missed some ground straps/cables? Bad grounding can cause all sorts of weirdness.

Is there anyone close to you with a Gap IID Tool? Might be worth giving that a crack, just to see if it has a better chance of connecting to the ECU. Would at least show that there is a comms problem of some sort.

Good luck mate!

[Denisrangie]

Yes - we had a couple of ground issues - this thing has grounds everywhere.
I put a scope on both the medium and high speed bus and the high speed bus is not balanced - one side has half the level compared to the other side.
So there is a clue.
My next steps will be to unplug each ECU connected to the HS bus to see if the levels correct themselves (try to identify the culprit).
I did the same on a ford Fiesta 2013 and it seems to have good data on both bus's and they are well balanced so I now know what they should look like.

Does anyone have any experience with swapping ECU's from a donor car - do they work or do they get ignored as the wrong VIN?
I also did try another OBD2 scanner and it also could not connect (works on other cars).
The Nano also works on a D2 so it seems fine (you need to swap the OBD2 lead from VC4 to the blue one).
Funny - the car will start and show all the faults on the dash and message centre so son bus activity is happening.

Will keep digging and hopefully solve it and will post the journey so it may help some other owner
Denisrangie
P[bawl]S - I am tempted to fix the D2 so I still can get out there.

[RANDLOVER]

Yes - we had a couple of ground issues - this thing has grounds everywhere.
I put a scope on both the medium and high speed bus and the high speed bus is not balanced - one side has half the level compared to the other side.
So there is a clue.
My next steps will be to unplug each ECU connected to the HS bus to see if the levels correct themselves (try to identify the culprit).
I did the same on a ford Fiesta 2013 and it seems to have good data on both bus's and they are well balanced so I now know what they should look like.

Does anyone have any experience with swapping ECU's from a donor car - do they work or do they get ignored as the wrong VIN?
..............................

I swapped the EAS (Electronic Air Suspension) module on mine with a new one from England, and it had to be reprogrammed using the VIN.

IIRC the earths to look at on a D3/4 are near the battery box, and there is a T-type connection under the front passenger door sill.

[Graeme]

Try swapping the transfer case module because in D3s and D4s it is a HS gateway that isolates the main modules from the less important modules and it doesn't need reprogramming.

[Denisrangie]

it's now at the point the engine will not run either - like a spreading cancer.
Mechanically the car is perfect.
I am going to park it for a few weeks to get it out of my head.
I have a good DF2 auto with the V8 so I am going to register that so I can get my off road hit over Xmas.
It need a bulb and wipers and a good detail and it is ready for rego.
Plan C would be a good D1 I also have (V8) manual - very reliable but needs a respray and a bit more with.
Both of these have way less computers to deal with.
I was toying with the idea of a new Defender (84 computers) but this whole D3 episode has me thinking - (NO WAY)

Why Vin Lock everything so you can't just swap the ECU's - 4 different data busses - is this really needed!
I had a good P38 that I crossed the Simpson in - the battery went flat and I did not use the car for a few months - The BCU refused to cooperate and would not allow new keys even with the software tool - so another Land Rover killed off by computer issues.
I can see why some are attracted to older Defenders - may be a truck and handle poorly but at least they seem to keep going.
Denisrangie

[PhilipA]

I understand on a Discovery Sport that the steering rack is VIN locked, so you cannot fit a remanufactured one or second hand one.
Don't ask what a new one costs.
I will bet that is similar on a new Defender also along with a lot of other hitherto replaceable components.
Regards PhilipA