There could be a number of things but let's start with these guides that will help identify the things we need to start checking:
We need to start with the crank sensor as that would be the most common cause.
The other possible cause would be a PCM issue. The best way to find this out would be monitoring the RPM on a graph with a scan tool. I suspect if the PCM is the issue the RPM will drop in a straight line down to 0. If you think about it, even when the engine shuts off, it doesn't just stop spinning which is what it would have to do in order to drop in a straight line down on the graph. The engine ramps down the speed and so the graph should show this. However, if the PCM is dropping out and shutting the engine off it will not see the ramp down of RPM. Here is a couple of reviews of scan tools that would be able to do this:
I attached the process of the crank sensor. I would suggest starting with that and go from there. Thanks
Images (Click to enlarge)
Saturday, November 28th, 2020 AT 6:44 AM