The 2015 350D Bluetec OM642 had a power outage and won't restart, even after a slow crank.

[ForumGuru]

Thank you in advance for your assistance.
There was no drama, noise, vibration, or smells when the engine stopped, and I was doing around 60mph. Keeps the temperature from rising too high. Everything is in order with the oil and water levels.
Ten minutes prior to this, the battery had no problems starting up. When I tried to turn it back on, it made the same clicking sound as a dead battery.
The AA arrived just as the machine was about to be jumped; it was turning extremely slowly and drawing a massive current.Before, there were no problems with the vehicle's operation.
Whether starting from a cold start or any other time, the cam chain makes absolutely no noise.
In order to prevent the alternator, air compressor, steering pump, pulleys, and compressor from seizing, I intend to remove the serpentine belt as suggested. I am not an expert on Mercedes vehicles, but I am a good mechanic. If this were the case, I would have detected burning or screeching sounds coming from the belt.
Even though I don't know much about the stop-start system, my suspicion is that the starter is faulty; however, I fail to understand how a faulty starter could ever cause the engine to stop running. I haven't been too concerned that the car's stop-start system has never worked.
I coasted a little after applying a lot of pressure, and the only time I realised the engine had stopped was when I pressed the accelerator and saw no revs; there was no power loss.
There was absolutely no indication of anything, and I have experienced catastrophic engine failure on multiple occasions. It abruptly ceased. There were no applicable codes when I used my merc-specific code reader on it. a handful pertaining to the instrument cluster's communication, but I fail to perceive any connection between the two. Absolutely nothing to do with engine timing or camshafts
I would greatly appreciate it if someone with more direct experience in this area could provide some feedback and suggestions for fixing the problem.Although I am familiar with cars in general, I don't know much about this particular model. I will try to remove the belt, but it seems like a pain, so I think other checks would be better to do first. It has seized, and that is my worst nightmare.

I am grateful.

[ForumGuru]

BTW, the mileage is 109k.

[Paqngo]

Verify all exposed wires for signs of damage or potential rodent infestation.

[Paqngo]

Apologies, I only just saw the dateline!

[Paqngo]

🤩