Press select to open the PDA, then enter the Cheat mode code. Close the PDA and re-open it. Use the D-pad to enter the codes while the PDA is open. Note: These cheats require the October 26th update from PSN to work.

Code Effect

right left down up right left down up All airstrikes
left right right left up up left up All Supplies
up down left right right left All Vehicles
L2 R2 R2 L2 R2 L2 L2 R2 R2 R2 L2 Cheat Mode
up up down down left right left right Give Nuke
up down left right left left Infinite Ammo
up down left down right right Invincible
up up up down down down Refill Fuel
up right down left up Unlock Costumes
up left down right up Unlock Grappling Hook

Unlockables

Trophies - Complete each condition to get the allotted Trophies. There are 24 Bronze Trophies, 11 Silver Trophies, 4 Gold Trophies, and 1 Platinum Trophy.

...And Justice For All (Silver) You verified all high value targets
Aces High (Gold) You captured all high value targets
Armageddon It (Bronze) You destroyed 25 buildings

Balls to the Wall (Gold) You mastered the Winching Challenge
Be Quick or Be Dead (Silver) You sniped 50 enemy vehicle drivers
Billion Dollar Babies (Gold) Be connected to EA Servers and earn $1 billion

Damage, Inc. (Silver) You used 20 airstrikes in co-op
Digital Man (Silver) You unlocked all shop items
Dirty Deeds (Bronze) You achieved maximum Universal Petroleum mood

Eat the Heat (Bronze) You performed a burnout

Forever Free (Bronze) You achieved maximum P.L.A.V. mood

Gone Shootin' (Bronze) You completed one of Fiona's challenges

Hail and Kill (Bronze) You destroyed 50 objects using melee
Heavy Metal Thunder (Bronze) You successfully completed 10 action hijacks
Hello, Hooray (Bronze) You acquired the PMC
Highway to Hell (Bronze) You completed 3 races
Holy Smoke (Bronze) You destroyed 50 Objects With a Grenade

Island of Domination (Bronze) You achieved maximum Pirate mood

Little Savage (Bronze) You destroyed 50 Objects with an RPG Launcher
Longing For Fire (Bronze) You achieved maximum Chinese mood

No Compromise, No Regrets (Silver) You battled for Caracas
No More Mr. Nice Guy (Silver) You pissed off everyone in Venezuela
Nothin' But a Good Time (Silver) You destroyed 200 objects from the gunner seat in co-op

Oil and Gasoline (Bronze) You recruited Eva

Partners in Crime (Bronze) You've experienced co-op
Pipeline (Silver) You captured all outposts for a single faction

Ride the Dragon (Bronze) You hijacked the tank in the villa
Runnin' with the Devil (Silver) You verified Blanco

School's Out (Bronze) You completed the tutorial
Shoot to Thrill (Bronze) You got 25 headshots
Stand Up and Shout (Bronze) You achieved maximum mood with the Allies

Tattooed Millionaire (Bronze) Be connected to EA Servers and earn $1 million
The Analog Kid (Bronze) You recruited Misha
The Hero and the Madman (Gold) You completed Mercenaries 2
The Rage (Bronze) You completed "Rescue Carmona"

We'll Burn the Sky (Silver) You unlocked all landing zones
Wheels of Steel (Bronze) You came in first during a co-op race
Wild One (Bronze) You recruited Ewan
World in Flames (Platinum) You earned all trophies in Mercenaries 2

You Better Run (Silver) You verified Carmona