How do you put codes in on gta 4?

Answer 1

if you learned how to actually spell cheat right, you wouldn't be asking this right now, but I'm a good sport, so, press up on the d-pad twice and so now you can enter the numbers. now learn to spell!

Answer 2

While in-game, press up twice on the d-pad to activate the dialing feature on your phone. Type in the code and press the call button. Doing this will automatically activate the code. To access previously typed codes in the future, press up once on the d-pad to activate your phone menu. Find the Cheats icon and press A. Then search through all of your previously entered codes and simply press A to activate them.