DESCRIPTION

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.