Mercury 225X Smartcraft Question

I have a 2004 225X with a Smartcraft System monitor gauge. The SCM reads one bank and I then have another wired temp gauge that reads the other bank. The Smartcraft gauge gave me a readout the other day that I have never seen and can't seem to get info on. It reads "S t l 1" on the readout. Anyone have feedback on what this means? Thanks

Mercury 225X Smartcraft Question