Starting System Description and Operation 6.6L / 8.1L

The starter has pole pieces that are arranged around the armature within the starter housing. When the solenoid windings are energized, the pull-in winding circuit is completed to ground through the starter motor. The hold-in winding circuit is completed to ground through the solenoid. The windings work together magnetically to pull in and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline 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 then applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding as battery voltage is now applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine starts, the pinion gear overrun sprag protects the armature from excessive speed until the switch is opened.

When the ignition switch is released from the CRANK position, voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now in the opposite direction of the current flow when the winding was first energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, cause the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter motor is turned off.

When the Ignition switch is placed in the start position B+ is supplied to the coil side of the STARTER relay, the powertrain control module (PCM) / engine control module (ECM) also receives the 12 V signal that crank has been requested, The PCM/ECM verifies the vehicle is in PARK and conditions are acceptable for engine cranking, the PCM/ECM will then ground the control circuit of the STARTER relay. With STARTER relay closed B+ is supplied to the starter solenoid and the engine will begin cranking.

When the Ignition switch is placed in the start position and Clutch Start Switch closed (clutch pedal depressed) B+ is supplied to the coil side of the STARTER relay, the powertrain control module (PCM) / engine control module (ECM) also receives the 12 V signal that crank has been requested, The PCM/ECM verifies the clutch pedal is depressed and conditions are acceptable for engine cranking, the PCM/ECM will then ground the control circuit of the STARTER relay. With STARTER relay closed B+ is supplied to the starter solenoid and the engine will begin cranking

Starting System Description and Operation 7.2L / 7.8L

The starter has pole pieces that are arranged around the armature within the starter housing. When the solenoid windings are energized, the pull-in winding circuit is completed to ground through the starter motor. The hold-in winding circuit is completed to ground through the solenoid. The windings work together magnetically to pull in and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline 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 then applied directly to the starter motor and it cranks the engine.

As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding as battery voltage is now applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine starts, the pinion gear overrun sprag protects the armature from excessive speed until the switch is opened.

When the ignition switch is released from the CRANK position, voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now in the opposite direction of the current flow when the winding was first energized.

The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, cause the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter motor is turned off.

With the ignition in the ON position, the ECM enables the ECM relay by grounding the control circuit of the ECM relay.With ECM relay closed, B+ is supplied to the coil side of the STARTER CUT relay.The ECM will ground the control circuit of the STARTER CUT relay based on information from the TCM (automatic transmission) that the vehicle is in PARK, and conditions are acceptable for engine cranking.With the STARTER CUT relay closed, ground is supplied to the control circuit of the STARTER relay. With the Ignition switch in the Start position 12V is supplied to the coil side of the STARTER relay and signals the ECM that CRANK has been requested. With the STARTER relay closed battery voltage is supplied to the starter motor and engine will begin cranking.

With the ignition in the ON position, the ECM enables the ECM relay by grounding the control circuit of the ECM relay.With ECM relay closed, B+ is supplied to the coil side of the STARTER CUT relay.The ECM will ground the control circuit of the STARTER CUT relay when a clutch start signal is received, clutch closed and conditions are acceptable for engine cranking.With the STARTER CUT relay closed, ground is supplied to the control circuit of the STARTER relay. With the Ignition switch in the Start position 12V is supplied through the closed clutch switch (clutch pedal depressed) to the coil side of the STARTER relay and signals the ECM that CRANK has been requested. With the STARTER relay closed battery voltage is supplied to the starter motor and engine will begin cranking.