Circuit/System Description

When the push to start ignition mode 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. For the manual transmission the ECM then verifies that the clutch is fully depressed. For an automatic transmission the ECM then verifies the transmission is in Park/Neutral and the brake pedal is applied. Once the required inputs are verified, the ECM then supplies 12 V to the control circuit of the starter relay. When this occurs, battery voltage is supplied through the switch of the starter relay to the starter solenoid.