Citroën Xantia

since 1993 release

Repair and operation of the car

System of ignition - petrol models

The system of ignition on an equal basis with system of injection of fuel is a component of the control system of the engine operated by uniform ECU (for more details see the Head of the Power supply system and release). On the majority ignition is organized according to the scheme without distributor. The main component of system is the module of ignition (DIS).

The DIS module represents the ignition coil with four conclusions and consists of two separate VV of coils, each of which provides ignition of fuel in two cylinders of the engine (one winding in cylinders the 1 and 4, second - 2 and 3). The principle of a "single" spark when each of spark plugs generates a spark twice for a running cycle of the piston - once at the end of a step of compression and the second on a final step is the basis for functioning of the module. ECU of a control system of the engine on the basis of information obtained from various sensors exercises constant control over installation of a corner of an advancing of ignition and the period of a charge of the coil.

On models of 2.0 l the structure of system of ignition switched on the detonation sensor. The sensor is installed on a head of cylinders and informs ECU on emergence of a detonation of fuel in the engine at increase of loading. The sensor reacts to change of intensity of vibrations, revealing thereby the moment when ignition becomes too early. ECU immediately issues the command for the corresponding correction of a corner of an advancing (towards delay), eliminating with that all negative phenomena.