There is not a cheat code that spawns a tank in "Grand Theft Auto IV." There are, however, many other codes that can still help out a player's game play.
Cheat codes are used by dialing phone numbers into the character's cell phone in "Grand Theft Auto IV." To restore his health, armor and ammo, dial 482-555-0100. To spawn a selection of weapons, dial 486-555-0100 or 486-555-0150. To lower his wanted level, dial 267-555-0100.
Using cheat codes can be very helpful and fun. Some codes temporarily disable certain challenges or achievements, however, so players should be careful which ones they dial. The challenges or achievements are only disabled for the duration the cheat is used.