The code will not stop the truck from moving. It sounds like something mechanical broke like a output shaft. Is it a 4 wheel drive? Is the transfer case in neutral? But the clunk sounds like something is broken or something in the drivetrain is broken. Have you also checked to see if the driveshaft is turning? You could have broken a spider gear or an axle on the rear end and the vehicle wouldn't move. So check and see if the driveshaft is turning.