Entering Samsung Codes on the Galaxy S4 - Verizon This is likely an embarrassing question, but I may not be the only one struggling.

I am trying to figure out a problem with my phone by using these secret dialer codes. I am entering these codes into my phone, but nothing is happening. When I call the entered number, I get the typical Verizon lady saying "The call cannot be completed as dialed..."

I specifically have used a code from this link (this addresses the problem I am having) and have tried multiple others from here*, but all give that same problem. Is there something that I am missing? Do I have to be a super user or something along those lines?

*Note: I know these may not be specific to my device, but some of these look to be universal regardless of manufacturer or model.
You shouldn't trust such a list of secret codes, simply because secret codes are not only device specific but mostly app specific.  

Secret Codes are generally defined by the applications installed on the device.
If you want to have a valid list of secret codes available on your device, you should use an automated secret codes crawler.

I recently developped an Open Source app that crawls AndroidManifest.xml files on your device to found secret codes, and allows you to execute the secret codes available on your device.
You can get it on the Play Store or on the GitHub repository Android-Secret Codes.

But keep in mind that sometimes, secret codes are just executing themselves silently (without visual hint)