The GEN III V8 engine is fitted with a Melco, 6-pole, 4-brush starter motor. This consists of a solenoid switch on a DC motor that has permanent magnet excitation. This has the advantage of low weight with high output torque.

The starter motor does not have field coil windings or pole shoes. These parts have been replaced by permanent magnets that are held in the pole housing by clips. The positive brushes are now part of the brush plate assembly.

The solenoid switch is used to activate the DC motor and has 2 windings, the pull-in winding and the hold-in winding. The pull-in winding has heavier wire and is grounded through the DC motor winding and brushes. The hold-in winding is grounded to the solenoid casing.

The planetary drive train consists of an internally toothed ring gear and 3 planetary gear wheels which rotate on sleeve bearings on the planetary drive shaft. The ring gear is keyed into the drive-end housing and is made from high-grade polyamide with mineral additives.

When the starter motor is operated, the armature turns the planetary gears inside the fixed planetary ring gear. This drives the planetary shaft at a reduced speed ratio (approximately 6.86:1) which turns the drive assembly. A fork lever in the drive end housing forces the drive assembly to slide forward and engage with the engine flexplate/flywheel ring gear to transmit cranking torque.

An internal clutch allows the drive assembly pinion gear to rotate freely when the engine starts. This prevents the armature from being driven at excessive speed by the engine.

The armature shaft is supported at each end by oil absorbent sintered metal bushes, one in the commutator end shield and one in the planetary drive shaft. These bushes require lubrication only at the time of overhaul. The front end of the armature has a gear profile. This meshes with the 3 planetary gear wheels. these in turn, mesh with the internal teeth of the ring gear.

A brush plate supports 4 commutator brushes. This plate is fixed to the commutator end shield with 2 retaining screws. 2 negative brushes are grounded to the pole housing. The 2 positive brushes are insulated from the pole housing and connected to the solenoid switch M terminal.

The battery cable supplies a constant connection from the battery to the solenoid switch . The ignition switch and either the park/neutral position (PNP) switch or the clutch pedal position (CPP) switch provide inputs to the engine control module (ECM). The ECM controls the activation of the start relay.

With the ignition switch in the START position and the automatic transmission in PARK or NEUTRAL, or the clutch pressed to the floor, current flows via the start relay to the solenoid switch. This activates the solenoid switch windings. The pull-in winding causes powerful magnetism to pull in the solenoid switch plunger. The hold-in winding holds the plunger in and the pull-in winding deactivates.

The solenoid switch simultaneously closes the switch contacts to connect terminal 30 to the DC motor and pivots the fork lever to engage the drive assembly to the flexplate or flywheel ring gear.

When the solenoid switch contacts close, current flows from the battery through the DC motor, which spins and provides cranking torque.

The engine control module (ECM) controls the operation of the start relay. When the ignition switch is turned to the START position , the ECM will enable the start relay for 1 second. If the ECM does not receive the correct theft deterrent signal from the powertrain integration module (PIM), it will disable the starter relay. If the ECM receives the correct signal from the PIM, it will continue to enable the start relay. When the engine has started and the engine speed is above 500 RPM, the ECM will disable the start relay, preventing starter engagement while the engine is running.