Opel Astra, Zafira

Since 1998 of release

Repair and car operation

Electronic control system of ignition (and injection) petrol engines

The general information, the description of principles of functioning and safety measure

The general information

The system of ignition of the petrol engine is integrated with system of injection of fuel and copes the uniform block of electronic control ECM (see the Head of the Power supply system and release). The ignition system consists of the engine management module (ECM), the switch of ignition, the ignition module (ICM) with the built in coils, spark plugs, high-voltage wires and the complete set of information gauges.

On all models considered in the present Management the system of ignition of direct type (without the distributor) is used.

On engines of 1.6 l SOHC and 2.0 l DOHC the ignition module consists of the coil of ignition and is equipped by four conclusions. Actually, in the module монтированы two separate coils of ignition, each of which on arriving with ECM to commands carries out giving ВВ of pressure simultaneously on two spark plugs (1 and 4, 2 and 3). Ignition is organised by a principle of "a single spark», that is each candle gives out a spark twice for a piston running cycle - in the end of a step of compression and in the end of a final step. As on a final step the mix in the combustion chamber does not move, no ignition in it occurs, despite искрообразование, whence the principle and has received the name.

On engines 1.4, 1.6 and 1.8 l DOHC are included in the ignition module four coils, - on one on the cylinder. Coils are placed in the general case established over spark plugs. The module design excludes necessity of application of high-voltage wires as coils are connected directly to spark plugs. ECM, on the basis of the analysis of data arriving from information gauges, according to the program of the built in processor, gives out on the ignition module the operating electric impulses which configuration unequivocally defines the ignition moment.

The corner of an advancing of ignition is established and corrected by the management module.

ECM gives out operating pressure on primary windings of coils of ignition, inducing in them a magnetic field. Pressure giving periodically interrupts that leads to disappearance of a field and, as consequence, - to production ВВ of pressure in a secondary winding. High-voltage pressure moves to spark plugs. The interelectrode backlash of spark plugs is exposed so that at giving on a pressure candle between electrodes occurred accompanied искрообразованием "breakdown". The spark Resulting "breakdown", provides ignition of an air-fuel mix. The moment of giving of an impulse on a candle is calculated by the module of management on the basis of the analysis of the data arriving from information gauges about current turns of the engine, position of cranked and distributive shaft, quantity of combustion of air submitted to chambers and so forth Besides listed, to the factors influencing functioning of system of ignition, the temperature of the engine and a mix detonation concern position throttle заслонки. For delivery of necessary data the management module is answered with corresponding information gauges. The information arriving from gauges, is used not only at definition of an exact times of giving ВВ of impulses on spark plugs, but also at realisation of working updatings of quality of a mix. The description of procedures of removal and installation of gauges is resulted in the Head of the Power supply system and release.

Turns of the engine and position of a cranked shaft are defined by the module of management on the basis of the analysis of the information arriving from the gauge of position of a cranked shaft (CKP). The inductive head of the gauge is located near to a gear rotor on a flywheel. At passage of a tooth by a head the gauge gives out on ECM a pressure impulse. One tooth on a flywheel is absent, its position corresponds to position 90 ° before ВМТ the piston of the first cylinder. During this moment the gauge gives the admission allowing the module to trace position of a cranked shaft. The gauge of position of a camshaft (CMP) informs the management block on what of pistons is in the end of a step of compression.

The information on loading on the engine arrives on ECM from a measuring instrument of weight of air (gauge MAF) and the gauge of position throttle заслонки (TPS). Loading level is defined by quantity of air soaked up in the engine, and corrected on the basis of the information arriving from the gauge of a detonation (KS). The detonation gauge is established on the block of cylinders and informs ECM about arising with loading increase premature detonation ignition of a mix in cylinders. The gauge distinguishes the moment of the beginning of a detonation on the increase of a vibrating background caused by knock in cylinders. At reception from the gauge of the information on occurrence of a detonation of air-fuel mix ECM, carries out a delay of an operating impulse of ignition, reducing an advancing till the moment of the termination of a detonation.

Gauges of temperature of the engine, position throttle заслонки, (depending on a complete set) transfer to speed of movement of the car, position of the selector of automatic transmission and activation of the conditioner of air ECM the additional information on a current condition of corresponding knots and car units. On the basis of the analysis of continuously changing entrance information, the management module carries out updating of a corner of an advancing of ignition, the moment of injection and quality of an air-fuel mix.

At failures in development of signals any of gauges ECM it is switched in emergency operation of functioning and starts to be guided stored in memory of the processor by the base installations, allowing to drive away the car under the own steam to a parking lot or on a car repair shop. Efficiency of return of the engine can is thus considerable decrease at the expense of the termination of continuous updating of working parametres, and the fuel expense, on the contrary, - to increase. The system of onboard self-diagnostics at detection of refusals of functioning of system brings a corresponding code of malfunction (the engine Electric equipment see the Head) in memory of the module.

It is necessary to remember that full diagnostics of a control system by the engine can be executed only with use of the special diagnostic equipment, allowing to read out brought in memory of the processor codes of refusals. The analysis считанной information allows to reveal quickly a source of refusal and to eliminate the reason of its occurrence.

Safety measures

In order to avoid damage of components of system of ignition, and also for the purpose of decrease in risk of reception of traumas, observe following safety measures.

• If the engine is not started, do not hold ignition of 10 seconds included more.
• Before a detachment of electroconducting of any of system components switch off ignition.
• Before connection and a detachment of the diagnostic equipment (for example, a stroboscope) switch off зажиганиею
• Do not suppose grounding of windings of the coil of ignition on weight.