July 19, 2010March 19, 2015 More secret iPhone codes by happyorright More secret iPhone codes. Most of these codes work. With an iPhone 4 the main secrete code of *3001#12345#* didn’t work. Said an error had occurred. I used this code on friends iPhone 5 and it worked immediately to go into the Field Test mode. Related Post Flash once again allowing hacks against Gmail user... 30 Years of Apple Design in Two Minutes (via alln... iPhone, iPad and iPod touch: Syncing photos via iT... Want to see a program in Apple Basic?