Had a weird thing happen last night. Got in the truck to start it, it started, ran fine for 2 seconds, then quit. I repeated this 4 or 5 times, each time it would run for the same amount of time then quit, as if you turned it off yourself. No sputtering, a clean cutoff. Went inside and came back out in 15 minutes, fires up fine. I searched this forum and others for a while and this seems to be a somewhat common issue, but no common fix. I'm leaning toward the ECU immobilizer module...I'm thinking it was either it was a quirk, dirty key or the module going bad- I'd love to hear other's thoughts/experiences with this or any advice you may have- thank you.