07 Starts and dies after 2 seconds

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.

 

I just had a similar issue happen to me on my 2007 5.7 . Turns out it was a bad wiring harness to my crankshaft position sensor. (I forgot the code #that popped). I replaced the harness with a Toyota 3 wire harness I found on Amazon. From what I learned it was sending faulty timing info to the ecm. The sensor itself was good. Was a relatively easy fix as the sensor is easily accessed underneath, just to the front of the transmission. It could be causing your issue. I hope that helps.

Ken...

 

Thank you for the reply, I will keep that in mind. It never threw any codes with me and it hasn't happened again, but it still leaves me wondering. Seems to be a touch and go issue with some of these trucks.

 

Watch the security light on the dash. Up near the clock in the center I think on 2007.

If they key is recognized it should light for a second or two as the key comes on then light goes off completely. This is the signal the ECU is seeing the correct key.

If you don’t see this when the issue is happening it’s because of the key. You could try a second key to verify.

If the light stays on or is flashing I pretty sure that means it’s not seeing the key correctly.