I'm confused. Are you trying to train him to use a puppy pad? If you want the puppy to go outside, only train him to go outside. Don't muddy the waters.
Puppies have accidents. Be consistent with using the outdoors as a potty spot, throw that dog a party and let them know you are super pleased. It takes time and consistency. Don't get discouraged.
Max, GSD 2002-2011
Shadow, GSD Not So Little Black Demon