Before Programming Powertrain Control Module

Ensure following conditions are met before programming Powertrain Control Module (PCM):

• There is no charging system concern. All charging system concerns must be repaired before programming PCM. Battery voltage is greater than 12 volts but less than 16 volts. Battery must be charged before programming PCM if battery voltage is low. A battery charger is not connected to vehicle's battery. Incorrect system voltage or voltage fluctuations from a battery charger, may cause programming failure or PCM damage.
• Turn off or disable any system that may put a load on vehicle's battery. Twilight sentinel, interior lights, Heating, Ventilation and Air Conditioning (HVAC) system, engine cooling fans and Daytime Running Lights (DRL) may put a load on vehicle's battery. Applying parking brake, on most vehicles, disables DRL system. Refer to Owner's manual.
• Ignition switch is in proper position. Tech 2 prompts you to turn ignition switch to ON position, with engine off. DO NOT change position of ignition switch during programming procedure unless instructed to do so. All Tech 2 connections are secure. Connection at Data Link Connector (DLC) is secure.