2007 e93 AC problems

[jarad35]

I have a 2007 e93 328i, and the AC is not cold at all, like the compressor is not kicking in at all.

There is refrigerant in the lines, I haven't had it vacuumed to make sure it is exactly correct, but when I connect to the AC computer (IHKA87) with INPA I see 0 bar for the coolant pressure (which I am pretty sure is the reading coming from the AC pressure switch, the scale runs from 0 - 40 bar).

I will order a new sensor, but I am not convinced that is the problem because I can't change the pressure reading by shorting the connectors with a variety of resistors. I measured the voltage at the sensor wiring connection, and got what seemed like odd readings. There are three pins on the sensor/connector, and at the connector, I measured 11.9V, 5.01V, and 13.9V between the pins and ground. I was expecting one of them to be a common, and the other two to be returns for the high and low pressure cutoff, but all three had + voltage. Does anyone know what the readings at the sensor should be, and where they come in on the IHKA?

I am trying to decide if I have a bad IHKA, which would be much better than the only other thing I can think of - a short somewhere in this system. Any suggestions would be greatly appreciated.

[jclausen]

The ac needs to be service with the real a/c machine the kind they have at shops. You can't dx anything until you know if it has the correct charge and psi. Then you move forward if needed