Truck shuts off 15 seconds after staring engine???

First thing I would do is get it to a real mechanic not a Petro parts changer.

 

Run and get the diagnostic codes from the ECM.
See what it has stored.

Then do some basic troubleshooting
Fuel or wire.

 

Go to a CAT house that is a simple engine to diagnose .. If it’s getting fuel then it’s something like a crankshaft position sensor , power to ecm or even key switch .. A competent mechanic will find issue PS if it’s power to ecm sometimes it doesn’t register a code because it thinks key was turned off

 

Probably not your case(with everyone looking it over)...but,I had a truck that dobe that.Was simply the coolant level Too Low for the coolant sensor to keep a signal.2 quarts of antifreeze and it was good to go.

 

My Century does that. Won't run if its very low just starts then dies after a bit.

 

My first thought also, if not that , then one of the other sensors.

 

Cat eng like you have in your truck has a crank cam speed sensor that goes in head behind air comp that will go bad and Eng will not run and not give a code sorry i did see this sooner buy it and put it in

 

low coolant sensor is a strong possibility

 

Mom. He broke it