Before Programming the Engine Control Module

The following criteria must be met before performing the programming or learning procedure:

• Vehicle system voltage
• There is no charging system concern. All charging system concerns must be repaired before programming a control module.
• Battery voltage is between 12 - 16 V. The battery must be charged before programming the control module if the battery voltage is low.
• Turn OFF or disable any of the following systems that may put a load on the vehicle battery:
  • Twilight sentinel
  • Interior lights
  • Daytime running lights
  • HVAC systems
  • Engine cooling fans, etc.
• The ignition switch is in the proper position. The scan tool prompts you to turn ON the ignition, with the engine OFF. DO NOT change the position of the ignition switch during the programming procedure, unless instructed to do so.
• All of the following tool connections are secure:
  • The connection at the data link connector (DLC)
  • The voltage supply circuits

DO NOT disturb the tool harnesses while programming. If an interruption occurs during the programming procedure, programming malfunction or control module damage may occur.