We have an error code SC546 any idea what that means. It just showed up.

This is a fuser code; it can be reset on newer models by pressing...

clear modes(yellow key)
1, 0, 7
clear stop (hold down until screen changes)

select copier sp

turn machine off with red rocker switch(likely on left side of machine)

wait 10 seconds and turn back on

If the code comes back, there is likely something malfunctioning on the machine, and it will require service. If not, this should get you by for awhile.

Yeah, what he said... Here is the info from the service manual:

SC546: Unstable fusing temperature
The fusing temperature varies 50°C or more within 1 second twice
continuously.
Possible Causes:
• Thermistor defective
• Poor connection of the fusing unit
• Power supply unit defective

I'd go with the idea that the thermistors (2 of them) probably have a significant build-up of toner, and should be cleaned or replaced.

Check your copy counter and see how many copies/prints it has:
Press User Tools/Counter button in upper left of the control panel, then select the touch-screen button 'Counter' in the lower right of the screen. The fusing unit is supposed to be serviced about every 120,000 copies/prints.

Generally an error like this will go away, initially, after performing the reset function the other poster listed, but odds are it will return soon, and the problem will only get worse.