Starting System: Description and Operation

STARTING SYSTEM

The starting system consists of the following:
- Starter motor
- Starter solenoid
- Starter motor relay
- Starter drive
- Battery
- Digital transmission range (TR) sensor
- Ignition switch
- PCM

The function of the starting system is to crank the engine at a speed fast enough to permit the engine to start. 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/flywheel 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 cranks the flexplate/flywheel 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/flywheel.

Automatic transmissions have a digital TR sensor mounted on the transmission. The TR sensor prevents operation of the starter motor unless NEUTRAL or PARK is selected.

Starting System - Anti-Theft Intervention
If equipped, the starting system is electronically controlled by the passive anti-theft system (PATS). The PATS recognizes the correct electronically coded ignition key and signals the PCM to provide a ground for the starter relay. The energized relay provides voltage to the starter solenoid, thereby allowing the starter motor to activate.