Description & Operation
When ignition switch is turned to START position, battery voltage is applied to Powertrain Control Module (PCM) crank request input. PCM verifies it has received a valid theft password from theft deterrent module and that shift lever is in Park or Neutral. PCM then grounds control circuit of starter relay. When starter relay is energized, it completes battery voltage circuit to starter solenoid "S" terminal.
When voltage is applied to solenoid windings, this creates movement of solenoid plunger and shift lever, causing drive pinion to engage flywheel and close solenoid switch contacts. See Fig 1 . When solenoid switch contacts close, starter motor energizes and cranks engine. As engine starts, pinion overrun clutch protects armature from excessive speed until ignition switch is opened and plunger return spring disengages pinion.