W220 not starting

[DocS55]

Hi all,
First post but have watched from the sidelines for years! My first ‘real’ problem with my car and I would like ideas where to go next.
W220 S500 L 2005, 7G transmission, M113 engine
My car has decided to not start. The dash lights come on, starter clicks and engine fan runs on full. From what I have read this appears to be a problem with the Engine Control Module.
This is what have I done so far:
1 - Battery appeared okay, but I put a new one in anyway and no change.
2 - I removed the modules either side in engine bay and under rear seat, 8 in total.
3 - I replaced the Right SAM as it had damage to board, but this made no change. All others appear okay.
4 - All fuses were removed, tested, cleaned and replaced.
5 - The starter was bypassed and engages engine.
6 - Starter relay tested fine.
7 - Checked Canbus under driver kick panel and footwell and passenger footwell. No corrosion, however, did get 4 of the paired leads reading 0. 1 of these relates to the AGW in the boot which was disconnected (separate issue!). I have not managed to trace back the other 3 yet as very busy at work, giving me limited opportunity.

Due to the current lockdown, my local garage has closed. I have a basic ELM Bluetooth and hand held Mactools OBD2/EOBD scanner, which have shown no DTCs.
I look at my options as:
1 - wait for local garage to open (I understand they use Snap on diagnostics)
2 - purchase an ECM and see if different faults appear. From what I have read, it still will not start due to EEPROM needing swapping/coding. Is there anyway I can do this?
3 - purchase a better diagnostic scanner that can trace fault/s & possibly recode?
4 - find local Indy with Star
5 - ??? suggestions please

I really would like my car back on the road and prefer not to wait for the indefinite lockdown to lift. I’m borrowing a car presently to get to work.
I may have missed some other bits I‘ve tried, as I’ve been intermittently working on it for the last 3 weeks.
Any ideas or suggestions are appreciated.
Thank you all in advance, keep safe, protect yourself and others, stay at home.

 

[pcthrillrider]

this might help

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[BlackC55]

Take it to your local MB specialist with a Star. It will save you ££ in the long run.New engine control units are not too expensive nowadays. Have you tested the voltage to the engine control unit? Has it got a supply and earth?

 

[stability]

You have over complicated things very very quickly keep it simply, it sounds like an earth problem to the starter motor this needs to be ironed out before moving into to the steps you have taken.

 

[DocS55]

Thank you all for your replies. Sorry for the delay replying.

pcthrillrider - I did take a very quick look at this before but due to time constraints and length of video I did not watch it all. I now have and I going to do a little more investigating.

BlackC55 - I would take it to an Indy or MB, however the car does not run added to the fact that my locals are in lockdown. The nearest MB that ”maybe” able to help is short staffed and over 35 miles from me. My car would be parked until a member of the team is available - no time frame given. As I said earlier, I really need my car as work is very busy at present and I’m borrowing.

stability - I removed starter, bench tested, cleaned and replaced. Continuity and volt drop okay. Earth seems good - you have got be thinking though, so I will recheck once more!

All these suggestions are great and I thank you once again. Is there a diagnostic scanner that anyone can recommend that can check the modules? I have seen the reviews from a link on this forum, however, it is an older link and I’m sure there maybe better scanners available today. Ideally one for more than one brand of car.
I am next off on Sunday, so will try and do these checks then. If anyone thinks of anything else, it is appreciated. I will update accordingly.

 

[wrdcc01]

Did you get a good earth continuity reading between the body and engine?