Could be, I tried it with a half a dozen different '13/'14 models off Craigslist last night and it worked like a charm on all of them, didn't try any older as I'm seeing those less and less.
Just tried it on the only '12 I could find listed locally and it was a no-go.....probably only good on '13's and newer?? Still handy though as the '13's and on tend to have the most different options, before '13 all you had was the SL and SVs and not as many options.
2012 SL purchased used 2/'16
2013 S w/QC purchased new
Juicebox Premium 60a L1/L2 EVSE, Ebusbar 16a L1/L2 EVSE
'12 EVSEupgrade'd 20a L1/L2 EVSE, '13 EVSEupgrade'd adjustable 6-20a L2, 6-13a L1 EVSE
Zencar 13, 20, 30a L1/L2 portable EVSE
GE Durastation 30a