30 degrees really isnt cold enough to gel #2 diesel fuel, so the 911 probably wasnt needed. However, changing the fuel filter anytime your machine is running a little rough or perhaps has stalled is a must. Their inexpensive and normally solve the issue or at the very least rule out a dirty filter. Moving on, when the machine died while you were running, did it beep 3 times first? If so, a code was generated from somewhere and told the computer to shut down the machine. If shut down by the computer, the computer will allow the machine to be re-started, but only for a short time before it beeps and shuts down again. If your not able to start the machine and it cranks over your problem lies elsewhere. Like Tom said above the pickup tubes are a maintenance item and do fail over time. If that is the issue, try adding more fuel to the tank so whats left of the pickup tube will draw fuel once again and your in business. You can also try jumping the starter solenoid, that will bypass any electronics as long as you engage the fuel shutoff to the open position. As far as resetting any codes, you cant. The only thing that will erase a code is when the issues is fixed. I assume you have a G series machine, not F?