I don't know if the ML150 G6 has this option in the BIOS, but you can see if you're able to tell it to keep running even if there's a thermal overload.
I just checked on a DL360 G7 to see where that setting is, and it's in "Server Availability" and then "Thermal Shutdown".
Just know that if you disable the thermal shutdown, there is a risk of damage if there's really something overheating. I would only consider doing this as an emergency measure until you've repaired the sensor (which generally means replacing the motherboard in your case).
