Car Owners Hub UK - Built by Drivers, for Drivers

Greetings all, A W204 C63 amg is mine.

The air conditioner's light began flashing suddenly. Error 919100 was displayed when I connected my icarsoft code reader, which indicated that the refrigerant level was outside of the allowed range.

The mechanics who looked it over assured me that the refrigerant level was just right.

I used the new compressor breaking in function in icarsoft the last time my air conditioner gassed up (about three months ago). It seemed to signal to the car that the system had been regassed, so the ac button stopped flashing and the air conditioner blew cold air.

This time around, I attempted to use this feature, but the climate control went into automatic mode, the AC light started blinking, and the entire unit stopped responding. The temperature and fan level are completely out of my control. Disconnected the AC fuse, performed a complete reset with the battery removed, etc., but nothing worked.

I tried the new compressor function in icarsoft again, and now this unit is unresponsive. I knew it wasn't a good idea, but I got a responsive used climate control unit from eBay. However, it still had the same AC refrigerant level code and the AC light was blinking.

At this point, I am baffled. Would greatly appreciate any assistance. Please inform me if anyone in the north west area has a laptop running Mercedes software; I am located in Cheshire.

The level cannot be accurately measured; only pressure can. Please tell me the values of the low and high pressures in the AC circuit.
The ideal low pressure while the engine is idling is approximately 30 psi. A pressure of 150 to 250 psi is considered high. The large range on the high pressure side is due to the fact that it is temperature dependent. You can check it yourself with a cheap gauge; I happen to have one in my car's trunk at the moment.
The compressor will not turn on in order to prevent damage if the pressure falls below a certain lever

My money is on one of those tacky gauges that only has colour coding on the bottom side. Install the correct gauges and inform us of the outcomes.

It seems like the air conditioning pressure sensor is to blame, according to the people I spoke to. The issue is completely resolved after spending £22. A single annoying sensor. It was a hassle to have to empty and refill the petrol tank after installation, but replacing the sensors was a breeze.

Yes, other manufacturers have sensors attached to valves so that they can be changed without gas loss. Mercedes isn't good at that.