If you want to cheat, you can do the following thing. Pause the game and press LT or RT. When the cell phone is highlighted, select "Dial" and enter one of the following numbers to call. Since then one of the cheat function will be enabled.
Full health = #3855432584
Infinite ammo = #2666
Infinite sprint = #777468
$1,000 = #66639
Repair car = #778
No police notoriety = #662677
No gang notoriety = #664262
Spawn 44 Shepherd at Crib = #74374373
Spawn 12 Gauge at Crib = #1242843
Spawn Ar-40 Xtnd Rifle at Crib = #27409863
Spawn AS12 Riot at Crib = #27127468
Spawn Baseball Bat at Crib = #22732255
Spawn GDHC .50 at Crib = #434250
Spawn Hand Grenade at Crib = #4736233
Spawn K6 Krukov at Crib = #56578568
Spawn Knife at Crib = #56433
Spawn MacManus Sniper Rifle at Crib = #62262687
Spawn Molotov Cocktail at Crib = #6656868
Spawn Nightstick at Crib = #6444878425
Spawn NR4 at Crib = #674
Spawn Pimpcane Shotgun at Crib = #74672263
Spawn Pipe Bomb at Crib = #74732662
Spawn RPG Launcher at Crib = #762538
Spawn SKR-7 Spree at Crib = #SKRSPREE
Spawn T3K Urban at Crib = #83587226
Spawn Tombstone at Crib = #866278663
Spawn Ambulance at Crib = #262852623
Spawn Anchor news van at Crib = #Anchor
Spawn Ant at Crib = #268
Spawn Aqua car at Crib = #2782
Spawn Baron at Crib = #22766
Spawn Betsy at Crib = #23879
Spawn Bootlegger at Crib = #2668534437
Spawn Bulldog at Crib = #2855364
Spawn Bulldozer at Crib = #Bulldozer
Spawn Capshaw at Crib = #2277429
Spawn Cavallaro at Crib = #228255276
Spawn Compton at Crib = #Compton
Spawn Cosmos at Crib = #267667
Spawn Destiny at Crib = #3378469
Spawn FBI vehicle at Crib = #324
Spawn Fer de Lance at Crib = #3373352623
Spawn Five-O at Crib = #34836
Spawn Gunslinger at Crib = #Gunslinger
Spawn Halberd at Crib = #4252373
Spawn Hammerhead at Crib = #Hammerhead
Spawn Hannibal at Crib = #42664225
Spawn Hollywood at Crib = #465599663
Spawn Jackrabbit at Crib = #5225722248
Spawn The Job (Hummer H1 limousine) at Crib = #843562
Spawn Justice at Crib = #5878423
Spawn Keystone at Crib = #53978663
Spawn Komodo at Crib = #566636
Spawn La Fuerza at Crib = #52383792
Spawn Mag at Crib = #Mag
Spawn Mockingbird at Crib = #66254642473
Spawn Nelson at Crib = #635766
Spawn Newman mail truck at Crib = #Newman
Spawn Nightingale at Crib = #64448464253
Spawn Nordberg at Crib = #66732374
Spawn NRG V8 at Crib = #67468
Spawn Quasar at Crib = #Quasar
Spawn Quota at Crib = #78682
Spawn Rattler at Crib = #7288537
Spawn Raycaster at Crib = #729227837
Spawn Reaper at Crib = #732737
Spawn Richochet at Crib = #742462438
Spawn Shogun at Crib = #746486
Spawn Socialite at Crib = #762425483
Spawn Taxi at Crib = #8294
Spawn Thorogod at Crib = #84676463
Spawn Titan at Crib = #84816
Spawn TraxxMaster at Crib = #87299627837
Spawn Tuasar at Crib = #882727
Spawn Varsity at Crib = #8277489
Spawn Venom at Crib = #83666
Spawn Vice 9 at Crib = #84239
Spawn Vortex at Crib = #867839
Spawn Voxel at Crib = #87935
Spawn Xenor at Crib = #14333
Spawn Zenith at Crib = #936484
Spawn Zimos at Crib = #94667
Spawn Zircon at Crib = #947266
Infinite car mass = #463464836277
Evil cars = #38452277
Bad Gas mode = #Badgas
Wrath Of God mode = #10
GameStop T-Shirt = #42637867
Also you can use the following phone numbers as cheat codes. Just pause the game and press LT or RT until the cell phone is highlighted, then select "Dial" and enter one of the following numbers to make a call:
List all phone numbers = 555-6666
Ambulance = 911
Big Willy's Cab = 555-819-8416
Brown Baggers = 555-3765
Chicken Ned = 555-2445
Crash Landing = 555-6278
EagleLine Yellow Taxi Cab = 555-018-0174
Eye For An Eye Voodoo = 555-5966
Foreign Power (car dealer) = 555-2046
Freckle Bitch's (fast food restaurant) = 555-6328
Grounds For Divorce = 555-9473
Impressions Clothing = 555-3248
Legal Lee's = 555-9467
Lik-A-Chick = 555-3863
On The Fence (pawn shop) = 555-7296
On The Rag Clothing = 555-5926
On Thin Ice = 555-2564
Rim Jobs = 555-3493
Stocks = 555-3626
Suicide Hotline = 1-555-ITS-OVER
The Dead Cow = 555-6238
TNA Taxis = 555-455-8008
Turbulence = 1234-567