The following are known Game Genie Codes for Zero Tolerance on SEGA Genesis.

• Infinite Ammo
  AAFT-CABY
  Note: For infinite weapons, vests, bioscans, etc. you must pick up the item first.
• Ammo Power-Ups Completely Fill Ammo if You Already Have Some
  REJA-C61W
• All Levels Are Secured
  A39A-LA7E
• Invincible
  AMNA-AA5E
• Bullet Proof Vest Takes No Damage
  AAHA-CAG6
• Bullet Proof Vest Takes 1/2 Damage
  TAHA-CAG6
• Bullet Proof Vest Takes 2X Damage
  AAHA-CEG6
• Bioscanner Doesn’t Run Out
  AAGT-CAHT
• Bioscanner Lasts Half As Long
  AAGT-CEHT
• Bioscanner Lasts Twice As Long
  TAGT-CAHT