2005 Chevy Tahoe for the past two weeks has been turning off every couple days. One time at a traffic light, a couple days later when I was sitting in the driveway with vehicle running. It will start up; new fuel pump, alternator, ignition switch and battery. Any idea what this may be? Please help!!!!

 

Check your main relays and look for any discoloration on their pins would be one thing to look at.
Relays can be erratic when the get old.
Dirty grounds are a issue also, there are many ground points.

 

If a crank sensor is preparing for retirement, that might mean it is opening up internally, that loss of signal would cause an engine shut down.
Does the engine stumble some before shut down or does just quit like you turned the key off?

 

Quit like you turned the vehicle off

 

Did you ever figure it out? Currently having the same problem I have no other symptoms