The ignition and recharging circuit comprises the battery, starter and alternator.

The starter consists of a d.c. motor supplied by the battery and an energising electromagnet.

With the alternator still and the ignition key in the MAR-ON position, the warning light in the instrument panel comes on and supplies the voltage regulator built into the alternator via terminal D+.

In these conditions the energising circuit (rotor) is enabled to earth by the regulator electronics.

With the alternator rotating through the effect of the variation in the rpm and the magnetic field, a three-phase alternating voltage is produced in the electrical circuit (stator) which, rectified by the diode bridge, can exit terminal B+.

When the upper fixed calibration level is reached (13.7 - 14.2 V) the battery is charged and the system supplied.

The efficiency of the recharging system is controlled by the Body Computer:

- the Powertrain Control Module sends the D+ signal to the Body Computer which monitors the efficiency of the alternator recharging system by recording two parameters: the voltage signal from alternator terminal D+ and the engine rpm signal that is also received from the Powertrain Control Module via the CAN.

- at key-on while the voltage is less than approx 5.5 V, the Body Computer indicates that recharging is insufficient; when the voltage exceeds 5.5 V, the warning light goes off.If, on the other hand, with the engine running (rpm higher than 700), the voltage drops below a threshold of 4.5 V, the warning light comes on constantly, possibly accompanied by a message in the display.

The Body Computer M001 - connector A - receives a direct power supply from the battery through the line protected by maxi fuse F01 of the engine compartment junction unit B001.

Pin 9 of connector E of M001 provides the Body Computer with a reference earth.

The ignition switch H001 is supplied by the engine compartment junction unit B001 via the line protected by fuse F03.

In the MAR-ON position, numerous protected ignition-operated circuits and services are supplied (INT and 15/54 lines): the ignition-operated signal 15/54 is sent to the engine compartment junction unit B001, whilst the INT signal is sent to the Body Computer M001, to pin 11 of connector E.

The ignition-operated signal INT/A, however, is sent to Body Computer M001 at pin 1 of connector E.

When the ignition key for switch H1 is turned to the extreme position (AVV) pin 50 - the starter A020 solenoid winding is supplied - pin 50.

Pin 30 of A020 - connector A - i.e. the actual motor, receives a power supply with the voltage coming directly from the battery A1.

The direct current produced by the alternator A010 (pin B+), connector B, is sent to the battery A001, passing through the motor A020.

When the alternator does not turn and does not therefore recharge the battery, an earth signal is sent from pin D+ - connector A - of A010 to Powertrain Control Module M010 - pin 17 of connector B: this is connected via the CAN line to Body Computer M001 and to instrument panel E050 and manages, as described above, the activation of the "generator" warning light on the instrument panel.