check engine light stays on on 2001 Mercedes-Benz C320

I'm getting code P0173 and P0115. Are they related?
Will P0115 go away if the car warms up????
Resetting the computer so the MIL light goes out keeps failing.

Asked by for the 2001 Mercedes-Benz C320
P0115 is a bad coolant temperature sensor or stuck open thermostat, P0173 is a fuel trim malfunction issue. Check this website
could both codes have something to do with pre cat O2 sensor and O2 sensor heater?
Is there a connection?