Circuit/System Description

When the ignition switch is placed in the START position, a discrete signal is supplied to the body control module (BCM) notifying it that the ignition is in the START position. The BCM then sends a serial data message to the engine control module (ECM) that crank has been requested. The ECM monitors the park/neutral position switch and the clutch pedal position sensor. If the transmission is in Park or Neutral, or the clutch pedal is pressed, and there are no DTCs that inhibit engine starting, then the ECM supplies voltage to the control circuit of the STRTR relay. When this occurs, battery voltage is supplied through the STRTR relay to the X2-S terminal of the starter solenoid. The starter solenoid energizes, and supplies battery voltage to the starter from the B terminal to crank the engine.