2005 Chevy Truck flooded

Well, first of all does the vehicle crank? What would be really bad is if it got water in the manifold and you went to crank it and got hydro lock.

First thing to do is clean and dry plugs, plugwires, coils sensors and try to start it
anything?

Well water and electrical don't mix. Obviously. But the computer is the last thing you want to condem as bad. Computers are quite resiliant and rarelly fail even after some severe punishment, and if you put a new computer in a truck that fried the old one without fixing what fried the old one you will just go in circles. The wiring fuses connections and odd components need to be dried and checked before changing the computer.

Well
first check for spark with a spark test can cut down the possiblities in half!

I hope your doing rear passanger side also?

The vehicle needs 3 things to start.
Spark, fuel, compression.

Since its a newer truck I wouldnt suspect compression is bad.

And now that its been throughly soaked with water next step would be to test for spark on all spark plug cylinders with a spark plug tester NOT grounding out a spark plug.

Well The first thing I would do is eliminate the door lock and head light problem, you don't want it killing your new battery but you need the battery hooked up to trouble shoot the engine. Try pulling the fuses for the head lights and door locks. This should kill the system. Remember you will need to fix this later and it may still drain on your battery so disconnect it over night. Then as blackop555 said check your spark and fuel systems. You probably already took care of this, but a good way to get all the moisture out of the cylinders is pull all the plugs, turn it over for a second and let it set like that for a few hours before putting the plugs back in. By the way I did the same thing to my Ford Ranger back in high school, after I got the cylinders dry it fired right up.

He meant Coils and Sensors. By coils I think he was refering to ignition coils which should be ok as long as the connections aren't wet. You have sensors all over your truck, but only worry about the ones that effect whether or not the engine runs. The IAC idle air control. MAP or MAF sensors which detect how much air is flowing. The crank and cam sensors should be ok since they are sealed. If you are getting spark and fuel to the motor the sensors are working well enough to get the motor running.

Unhook all but cam and crank sensors, if they get moisture in them and short out they will throw a false code, but the pcm will still accept it as correct!

And by coils I meant ignition coils they cannot get wet or they will not work dry them out and see how it goes. Just check and dry all you can.

Try to be more specific. I don't know exactlly where every sensor is on your engine, but if you let me know which sensor your looking for I can give you some pointers for looking for it. Are you getting Fuel and Spark yet?

Yes, we need those answers!