Q: What could be wrong with my vehicle? It stalled on the highway.

Hi, first task is to check for the problem codes that are setting the Check Engine Light. Since you have a "hard stop" failure, this become even more important.

First level isolation is to see if you have spark, or if this is a fuel issue. If you have spark, does it start briefly by spritzing a bit of starter fluid into the air cleaner when trying to start it.

If no spark, check fuse for ignition, then "walk the electrical power path" from the ignition switch to the coil, ignition module, ignition pickup in the distributor - components that would affect all cylinders at once. If it’s fuel - check fuel pump fuse, relay, and listen for the pump running when you attempt to start it.

To avoid any unnecessary repairs, I would recommend having a no start inspection completed by a mobile, professional mechanic, such as one from YourMechanic, who can come to where the truck is located to diagnose this problem, get an accurate assessment of damage and cost estimate for repairs.