When the ignition switch is on, battery voltage is applied to one side of the crank relay in the underhood accessory wiring junction block through circuit 3, the PCM-BCM Fuse in the fuse block, and circuit 439. When the ignition switch is turned to START, voltage is fed to the powertrain control module connector C2 terminal 23 through circuit 5, the CRANK SIGNAL Fuse in the fuse block, and circuit 806 through the underhood accessory wiring junction block. Power is always provided from the CRANK MaxiFuse in the underhood accessory wiring junction block to the common side of the crank relay contacts. When the powertrain control module sees the crank signal and determines that conditions are OK for a crank, it supplies ground through circuit 625 to the crank relay. The crank relay now has both power and ground to the relay coil, causing the relay to pull in. When this happens, and the gear selector is in either PARK or NEUTRAL, the power at the relay common contact is passed through circuit 1737, the transaxle range switch and circuit 6 to the S terminal on the starter solenoid.

When voltage is applied to the starter solenoid S terminal, both solenoid windings are energized. The circuit through the pull-in winding is completed to ground through the starter motor. The windings work together magnetically to pull in and hold in the plunger, which moves the shift lever. This action causes the starter drive assembly to rotate as it engages with the flywheel ring gear on the engine. At the same time, the plunger closes the solenoid switch contacts in the starter solenoid. Full battery voltage is applied directly to the starter motor, which cranks the engine.

When the solenoid switch contacts close, voltage is no longer applied through the pull-in winding, as battery voltage is applied to both ends of the windings. The hold-in winding remains energized, and its magnetic field is strong enough to hold the plunger, shift lever, drive assembly and solenoid switch contacts in place to continue cranking the engine.

When the ignition switch is released from the START position, battery voltage is removed from circuit 5, the CRANK SIGNAL Fuse, and from circuit 806 to connector C2 terminal 23 of the powertrain control module. The PCM then removes the ground from circuit 625 to the crank relay. This causes the crank relay to release, opening up the relay normally open contacts. This removes the power from circuit 6 to the S terminal of the starter solenoid and the junction of the two windings. Voltage is applied from the motor contacts through both windings to ground at the end of the hold-in winding. However, the voltage applied to the pull-in winding opposes the voltage which was applied when the winding was first energized. The magnetic fields of the pull-in and hold-in windings now oppose one another. The return spring causes the drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter circuit is turned off.

This vehicle is equipped with the Passlock theft deterrent system. This system contains a Passlock sensor. The Passlock sensor is part of the ignition lock cylinder assembly. The Body Control Module (BCM) interfaces with the Passlock sensor.

When turning the ignition switch to the START position with the proper key, the Passlock sensor generates an analog voltage signal, which is sent to the BCM. This analog voltage signal is of a specific value to the vehicle, and varies from vehicle to vehicle. When attempting to start the engine, the BCM compares a preset stored analog voltage value with the signal coming from the sensor. Because both values match, the BCM sends a fuel enable password via the Class II Serial Data Line to the Powertrain Control Module (PCM). As a result, the PCM enables the crank relay, and allows fuel delivery to the engine.

When attempting to start the engine by means other than using the proper key in the ignition switch, the Passlock sensor sends a analog voltage signal of a different value. The BCM compares the preset stored analog voltage value with the signal coming from the sensor. Because both values do not match, the BCM sends a fuel disable password via the Class II Serial Data Line to the Powertrain Control Module (PCM). As a result, the PCM disables the crank relay, and does not allow fuel delivery to the engine.

For more information regarding the Passlock theft deterrent system, refer to Theft Deterrent in Body and Accessories.