System Overview

System overview

General




This document describes the basic principles of the design and function of the generator (GEN), irrespective of the make.
The generator provides power consuming components with current whilst the engine is running and maintains battery charge. The generator (GEN) is often mounted on the front edge of the engine.
The output of the generator (GEN) depends on engine speed. When the engine is idling, the generator (GEN) operates at approximately half of maximum output. When the engine is idling with many power consuming components engaged, the generator (GEN) may be unable to maintain full battery charge.
In cold conditions the capacity of the battery to receive charge is lower than at room temperature. This means that, when the engine is idling for a long period with a large number of power consuming components connected, the battery may discharge.
If the generator charge is cut, the power consuming components of the vehicle are only supplied with energy from the battery, which means that the battery will eventually run flat.
First of all the generator (GEN) creates an alternating current (AC) which is converted to a direct current (DC) in the rectifier bridge.
The alternator has a built-in charge regulator (also known as the alternator control module (ACM)).
The charge regulator is connected to the engine control module (ECM) and communicates using LIN communication.
The auxiliaries belt transfers power from the crankshaft pulley to the auxiliaries such as the power steering pump, air conditioning (A/C) compressor, and the generator. An automatic belt tensioner is used to adjust the belt tension. The belt is a Poly-v-belt.
For 6 cylinder engines, the generator is directly connected to a gear wheel transmission via a coupling.




The generator (GEN) and charge regulator are diagnosed by both the central electronic module (CEM) and the engine control module (ECM).
The charge indicator lamp in the combined instrument panel is controlled by the driver information module (DIM) via signals from the controller area network (CAN).