The ignition and recharging circuit comprises the battery, starter motor and alternator.The starter motor consists of a d.c. motor supplied by the battery and an excitation electromagnet. When the ignition key is turned (for versions with passive entry / keyless go, when the knob is turned; see Wiring Diagram E5010 Starting and Recharging NPE) to the extreme position (AVV), the motor windings are supplied, producing electro-magnetic forces that allow the rotation of the actual motor pinion. This simultaneously activates the electromagnet that operates the mechanism that causes the pinion to mesh with the flywheel ring gear and thus turn the crankshaft. See E5010 STARTING AND RECHARINGThe alternator recharges the battery using the force generated by normal engine rotation. The alternator shaft (rotor) is turned by the crankshaft via a belt.When supplied by an excitation current, the rotor generates a magnetic field that sets up an alternating current in the fixed winding (stator). A rectifying diode bridge on the back of the alternator allows the alternating current to be rectified to a direct current that is sent to recharge the battery.A voltage governor, also built into the alternator, maintains the power supply at a constant voltage (14 V) regardless of the load variation range and engine speed.Recharging system efficiency is controlled by the Body Computer, which receives and measures the D+ signal from the alternator with the engine running.If a fault is detected, an appropriate message is displayed on the control panel matrix display.The Body Computer also downloads the battery voltage within a range from 18V to 6V.The information is then supplied via the CAN network to the other electronic units on the car so that certain appliances may be cut out if the battery voltage drops.Start-up may be inhibited by a battery disconnection switch in the boot. Once this is open, it cuts off the power supply to the entire car. This occurs in the case of a signal from the inertia switch or any event that could jeopordise the driver''s safety. The switch can, however, be reacivated manually by the driver.The car engine cannot be turned on unless the gear lever is set to N (neutral) or P (Parking) at the tiem of start-up. If the gear lever position is not positioned as described above, the power supply to the starter motor is inhibited. This function is managed by a dedicated relay in the junction unit on the engine bay.If the Passive Entry / Keyless go option is fitted, the vehicle is equipped with an electronic steering lock managed by a dedicated control unit (Wiring Diagram E7065 Electronic steering lock). If the steering is electronically locked, the vehicle cannot be started up until it is unlocked first. On versions with automatic transmission, the brake pedal, which sends the steering release signal, must be pressed. See E7065 ELECTRIC STEERING LOCK