So undercharged, should be close to 100 psi at that temp. The second scale from the center is temperature and should be pretty close to ambient when the system is static and equalized. I'm not finding any thing saying what pressure the BCM needs to see to allow the compressor to run. If you have a scan tool, you can check what the BCM is seeing for pressure. I suppose you could briefly jump the relay to see if the compressor comes on.
2010 Equinox LT V6 AWD