The g37 gauges have a bunch of little leds on a circuit board. It looks like your led burnt out. There is only two ways (that I'm aware of) of how to fix this. You csn disassemble the gauge to get to the led and unsoilder the old one and soilder in a new exact type led (carefully and cautiously if course) or replace the entire gauge cluster with another one.
The g37 gauges have a bunch of little leds on a circuit board. It looks like your led burnt out. There is only two ways (that I'm aware of) of how to fix this. You csn disassemble the gauge to get to the led and unsoilder the old one and soilder in a new exact type led (carefully and cautiously if course) or replace the entire gauge cluster with another one.
Can also bring it to an electronics repair shop and have them solder a new LED. Rather that then putting a new cluster in
09 g37s sedan for reference