Hello gentlemen. I have a 2004 W203 C class 180 Kompressor. 2 days ago I took a 50km drive to a water park. Halfway through the drive, the car completely shutdown while doing maybe 15kph (8mph). I pushed it to the side of the road, then after 15 minutes it started and ran fine until my destination. On the drive home, again, going about 20kph (15mph), car completely shutdown and did not start until now (2 days). Brand new battery (4 months old).

What I mean by complet shutdown. Engine stops, ignition system locks ( I take the key out of ignition, then it won't let me even turn the key, nor crank the car, doesn't even make the immobilizer sound), dashboard completely off ( not even the hazards light work). Now the dashboard is frozen to when it shutdown. Basically the only things that work are the radio( original), the interior reading lights and the headlights and stoplights if I turn them on. I can't lock the car, or even unlock it from the remote. I have to open the driver door with the physical key to get in the car. Even then, nothing comes on the dashboard (usually the dashboard lights up). If I try to unlock or lock the car, the only things that open are the trunk and the fuel door).

History of the issue:

Had this car for 5 years, mainly sat parked, done only 7000 km (4000 miles). Serviced it, everything good. 3 years ago, the car shutdown completely while driving, then after 10 minutes started like nothing happened. Went to a guy that said he's a Mercedes wizard and the told me the problem was with the ignition system, that it doesn't read the key. He didn't want to tell me exactly what he did or what he changed, but the car worked fine.

1 year ago, it happened again but only once and right as it shutdown, I could start the engine again mid drive.

3 months ago, I went to start the car in the parking lot ( I do this every week if I know I won't drive it as much, just to make sure everything is good, I keep it running for 10 mins then shut it off), and it won't start. Couldn't unlock the car, everything dead, no dashboard no nothing. Came back in the middle of the night and she unlocked and started perfectly.

One notable thing is that one time around 2 years ago, while I was driving, the low fuel error came on the dashboard and it said I was on reserve fuel. The same thing happened 2 days ago, on my way to the water park. This time, I saw the error for 3 seconds before the car shutdown again. Waited a bit and then started and drove perfectly, with no warnings or errors.

I surfed the whole internet to find the answer and spoke to 3 mb mechanics and they had no idea where to even start. From the internet I say that maybe the issue is with the starter motor, the CPS sensor and the fuel pumps ( I am on half the tank, I saw the issue where the transfer pump gets dry and shuts down the engine).

These are all reasonable, but no way does it explain why I can't unlock the car, why I can't even crank, why no dashboard light, why NO HAZARD LIGHTS, and everything from above. Also I took the key apart and cleaned the IR sensor, still no luck.

I will attach a link to a video I took so if anybody knows and wants to help, you can understand the issue better. I don't know what other details to give because this is already too long but will answer any questions. I really like this car and don't want to get rid of it.