Renault Megane, Scenic

Since 1996 of release

Repair and car operation

Ignition system - petrol models

The ignition system is united with system of injection of fuel, and make a uniform control system of the engine (address to the Head of the Power supply system and release more in detail). Depending on model, there are two possible types of system of ignition.

System with the distributor (engine E7J)

Engine E7J is equipped by the distributor; besides, the ignition system includes the module-amplifier, one coil of ignition, the gauge of speed/position коленвала and the detonation gauge.
Depending on the information received from various gauges, the electronic module of management calculates the moment of ignition/time of a food of the coil of ignition, optimum for certain turns of the engine and loading, ECU switches the amplifier block, operating a primary (low-voltage) chain of the coil of ignition. It leads to high voltage occurrence in a secondary winding which then on ВВ to wires is distributed to a corresponding spark plug.
The distributor is fixed on the left end of a cam-shaft. Pay attention that its position has no influence on the ignition moment, a power-current is transferred from the ignition coil to a candle. The signal of the moment of ignition is completely supervised by the electronic module of management.
On the block of cylinders the gauge of a detonation which informs the electronic module of management on the beginning of "detonation" of the engine is established. This device is sensitive to certain frequency of vibration, detonation impulses thus are found out at early ignition. The detonation gauge sends an electric signal to the electronic module of management which reduces installation of an advancing of ignition, "detonation" - a corner of an advancing of ignition will not stop yet then gradually comes back to "normal" value. Thus the corner of an advancing of ignition is supported as far as possible close to a detonation threshold - the most effective installation for the engine under normal conditions works.

System without the distributor (engines K7M, F3R and F7R)

Engines K7M, F3R and F7R are equipped by system of ignition without the distributor which copes ECU, and consists simply of two ВВ coils of ignition, the gauge of speed/position коленвала and the detonation gauge. Each coil of ignition serves two cylinders (one feeds spark plugs of cylinders №1 and №4, and another - cylinders №2 and №3). Ignition coils work by a principle of "a single spark”, that is the spark in spark plugs slips twice for each cycle of the engine, on a step of compression and on a release step. The electronic module of management uses signals from various gauges, calculating the demanded moment of ignition and time of a food of the coil of ignition. Functioning of the gauge of a detonation is described above - pay attention that on engines F3R it is established on a head of the block of cylinders.

Precautions

To prevent damage of components of system of ignition and to reduce risk of reception of a trauma, it is necessary to observe following precautions.
a) Before separation of electroconducting of system switch off ignition.
b) Before connection or separation of any diagnostic equipment (for example, a stroboscope) check up, that ignition has been switched off.
Do not close on the earth of a chain of primary or secondary windings of the coil of ignition.

The pressure created by contactless system of ignition, it is considerable above the ignition made by usual system. Be extremely cautious at work with system at the included ignition. People with вживленным a warm electrostimulator should not concern chains of ignition, components and the diagnostic equipment.