Since open turns on the fan that must signal high pressure to the IHKA so shorting the circuit would probably signal low pressure (low freon) and the system would not turn on. Anyway why would you want to replace the sensor if you suspect the problem was the connection? If you do need to change the sensor there is a chance that there is a schraeder valve under it but maybe try to verify that(maybe someone can chime in on that) before hand. Having the system work after cleaning the connections doesn't really match with the theory of operation of the sensor unless the IHKA is reacting by shutting down the system if it sees confusing readings. Interesting.

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1988 325is (purchased new) sold
2004 X5 3.0 2005 X3 2.5
2008 X5 3.0 (new to me)