2012 Tenni won't start

Hi all
went to take Tenni out for a spin, click then all shuts down and I hear a motor running probably the idle motor. Turn the key off then back on dsah sweeps normally, lights on,everything looks good, click same again all shuts down and idle motor running.
It started normally a couple of weeks ago, puzzling. Any thoughts?
Checked all fuses, checked MPH startus mod, no ECU errors, but instrumet panel errors:DSB01 (Key code read not recognized) and DSB07 (Oil sensor failure).
Now nothing lights up when I turn the key and it shows the ECU disconnected diagram.
Any help or suggestions much appreciated.
Cheers

I would get the batt load tested. Sounds like it's only got surface charge. Also check all cables for crud, on the batt & on the block for ground.

OK

Make sure to check the - cables under starter cover standoffs they get corrosion.

SORTED : it was the stupid wire to the solenoid that wasnt making good contact, jiggled it and pushed it in properly, started immediately. All good.
Thanks for the suggestions