Circuit Description

The main relay, is controlled by Powertrain Control Module (PCM). PCM provides a ground for relay coil anytime ignition is on. Main relay supplies ignition positive voltage to many engine control systems and components. The following components receive power from main relay:

• Fuel Pump Relay
• Fuel Injectors
• Mass Airflow (MAF) Sensor
• Evaporative (EVAP) Emission Control System Solenoids
• Exhaust Gas Recirculation (EGR) Valve
• Idle Air Control (IAC) Valve
• Powertrain Control Module (PCM)