I assumed if your car wasn't reading the key there would be a light on the cluster? I've given a few suggestions on a different thread already. And you don't post whether you tried any of them or not. I've yet to see an ecm just crap out while driving on one of these cars but it's still possible. Doubtful though. I haven't seen an engine fail either mind you. My guess is wiring problem. Broken wire or corroded connector somewhere. Good luck...
Dealers just call tech line and do what they are told to do, at least thats what I'm told by our dealer when they have not idea wtf is wrong. Though rumor has it some are actually mfg trained specialists.
Mirage videos:
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View my fuel log 2014 Mirage SE wussie cvt edition. 1.2 automatic: 37.7 mpg (US) ... 16.0 km/L ... 6.2 L/100 km ... 45.3 mpg (Imp)