7B Activation, map cooling (ODBII:P1622)

[barksten]

I have a Z3 2.8 year 2000.
I bought a ODB-scanner and got the ECU fault code "7B Activation, map cooling (ODBII1622)".
When checking the ECU data stream I've noticed some weird values:

On a cold engine (>24h since running)

coolant temperature, engine [°C]	83.32
coolant temperature, radiator outlet[°C]	81
Oil temperature, engine[°C]	104.80
intake - air temperature[°C]	73.95

Starting the engine (idle)

coolant temperature, engine [°C]	87.38
coolant temperature, radiator outlet[°C]	81
Oil temperature, engine[°C]	103.93
intake - air temperature[°C]	74.23

Stopping the engine again

coolant temperature, engine [°C]	143.68
coolant temperature, radiator outlet[°C]	81
Oil temperature, engine[°C]	110.02
intake - air temperature[°C]	74.23

I can also stream some generic OBDII values which reads:

Engine coolant temperature	46°C
Intake Air Temperature	27°C

which to me seems more realistically.

My concern is the constant 81 on radiator outlet.
My guess is that it represents the sensor that looks like this:

I tried to disconnect the cable from the sensor but it still reads 81 in the scanner!

Does anyone have a clue and some suggestions how to proceed?
I guess I can try to find another sensor and connect it to the cable to see if I get some other readings...