Mercedes of the S-class W202

1993-2000 of release

Repair and operation of the car

Mercedes W202
+ 1.2. General information
+ 2. Maintenance
+ 3. Engines
+ 4. Lubrication system
+ 5. Cooling system
+ 6. Heating, ventilation
- 7. System of ignition
   7.2. Safety measures at repair of electronic system of ignition
   7.3. Ignition coils
   + 7.4. Spark plugs
   + 7.5. Device of a preliminary warming up of the diesel
+ 8. Fuel system
+ 9. Transmission
+ 10. Running gear
+ 11. Steering
+ 12. Brake system
+ 13. Body
+ 14. Electric equipment
+ 14.2. Electrical circuitries

7. System of ignition

7.1. Introduction

GENERAL INFORMATION

The system of ignition develops sparks which ignite the gas mixture which is let in cylinders of the internal combustion engine. To develop the powerful igniting spark, in ignition coils tension of the rechargeable battery will be transformed from 12 Volts approximately to 30000 Volts.

Petrol engines of the S-class have the statistical distributor of ignition of high voltage, so-called direct ignition. In such system of ignition there are no moving details and the traditional distributor of ignition equipped with the runner. Thanks to it there is no wear of these details any more and operational reliability increases.

Actuating of the igniting sparks by means of coils of ignition is carried out directly by means of the control device of the engine which also operates system of injection of gasoline. At the 4-cylinder engine of the coil of ignition are established on the block of cylinders of the engine, and at the 6-cylinder engine – under a casing of wires of high voltage of a cover of a head of the block of cylinders. Each two cylinders receive the igniting sparks from one general coil of ignition. At the same time one ignites gas mixture in a step of its admission in the corresponding cylinder. For starting reliability at launch of the cold engine several igniting sparks on one working piston stroke (so-called multispark ignition) are developed.

1. Ignition advancing corner
2. Loading
3. Rotation frequency

The control device which is based on the characteristic of ignition which is saved up in memory by means of electronics is used to definition of the correct moment of ignition. Thanks to it it is possible to coordinate rather easier among themselves various service conditions, for example, other quality of fuel.

The system of anti-detonation regulation at engines, since the working volume of cylinders in 2,2 l, promotes operation of cars with a high compression and smoothes use of fuel of various quality. At the 4-cylinder engine on the block of cylinders of the engine one is established, and at the 6-cylinder engine two sensors of detonation combustion. They regulate detonation combustion in the engine and exert on it impact by means of the corresponding impulses arriving from the control device of the engine, changing the ignition moment towards late. Thanks to it the detonation of the engine and emergence of malfunctions in it is prevented.

If in the 1,8 / 2,0 l engines only gasoline of poor quality is mainly used, then by means of the coordinating plug in a motor compartment ignition has to be switched to other characteristic.

At repairs of electronic system of ignition it is necessary to follow safety regulations to avoid traumatizing the persons who are engaged in these works or damage of system of ignition.