Unfortunately the "key dance" is pretty limited in function compared with a scan tool on a JK's. Why.... only Jeep knows
So its a "easy" test but by no means a compete one. And even less useful on a squeezel as they are pretty poorly supported on the code front at the best of times.
Many people have had good results with cheap ( like $10 ) Bluetooth OBDII adapters ( some are complete rubbish however... ) and trial phone software..... but remember OBDII is a generic protocol and manufacturers are free to add their own codes to it for vehicle specific faults that freeware tools may not be able to "translate" back from gibberish.