Starting System: Description and Operation

Starting System

The starting system consists of the following components:

- Starter motor

- Starter motor relay

- Transmission Range (TR) sensor- automatic transmission

- Clutch cutoff switch- manual transmission

- Battery

- Ignition switch

- PCM

- Start diode

When the key is placed in the START position, the starter relay is energized and this sends current to the starter 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 flywheel until the ignition switch is released from the START position.

An overrunning clutch in the starter drive protects the starter motor from excessive speeds during the brief period before the driver releases the ignition switch from the START position as the engine starts.

Vehicles equipped with an automatic transmission have a TR (Transmission Range) sensor mounted in the transaxle. The TR (Transmission Range) sensor prevents operation of the starter motor unless NEUTRAL or PARK is selected.

Vehicles equipped with a manual transaxle have a clutch cutoff switch mounted on the clutch pedal bracket. The clutch cutoff switch prevents operation of the starter motor unless the clutch is fully depressed.

One-Touch Integrated Start (OTIS)

The vehicle has One-Touch Integrated Start (OTIS) , a computer-assisted cranking system. This feature assists in starting the engine. If the ignition key is turned to the START position and released when the engine begins cranking, the engine may continue cranking for up to 10 seconds or until the vehicle starts.

Once the ignition is turned to the START position and the vehicle is in NEUTRAL or PARK or the clutch pedal is depressed, the PCM reads starter motor request from the ignition switch and gains control of the starter engagement. The customer is no longer in the loop after the initial crank request, the customer may release the key to the RUN/START position. The PCM will disengage the starter motor based on the following events:

- The engine is started (rpm threshold)

- A set time has been exceeded (calibrated)

- The ignition key has been turned to the OFF position