Starting System: Description and Operation

Starting System

The starting system consists of the following:

- Starter motor

- Starter motor relay

- Starter drive

- Battery

- Ignition switch

- PCM

- Transmission Range (TR) sensor

The function of the starting system is to crank the engine at a speed fast enough to start the engine. When the starter solenoid is energized, a magnetic field is created in the starter solenoid windings. The iron plunger core is drawn into the starter solenoid coil, and a drive lever and pin connected to the starter drive engages the drive pinion gear to the flexplate ring gear. When the plunger is pulled all the way in, the contact disc closes the circuit between the battery and the motor feed terminals. This sends current to the motor and the drive pinion gear turns the flexplate to start the engine. When current flows to the starter motor, the starter solenoid pull-in coil is bypassed, and the hold-in coil keeps the drive pinion gear engaged with the flexplate.

The automatic transmission has a TR (Transmission Range) sensor which prevents operation of the starter motor unless NEUTRAL or PARK is selected.

This vehicle has a PCM-controlled cranking system. When the ignition is turned to the START position, the PCM receives voltage from the ignition switch and activates the starter relay, which engages the starter. The PCM will keep the starter engaged, even if the key is released to the RUN position, until any one of the following conditions is met:

- The engine is started (rpm threshold met)

- A set time is exceeded (10 seconds)

- The ignition key is turned to the OFF position