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

7.2. Safety measures at repair of electronic system of ignition


At electronic systems of ignition secondary tension makes up to 30 kV. Under adverse circumstances, for example, at the increased humidity in a motor compartment, peaks of tension can punch isolation. If in this case adjoin to details of system of ignition, then it can lead to an electroshock.

To avoid traumatizing the persons who are carrying out these works and/or damage of electronic system of ignition, when carrying out repair work in cars with such system it is necessary to pay attention to underwritten rules.

At the working engine or at its start do not touch by hands of a wire of high voltage and do not pull together it with hands.

Only at the disconnected ignition disconnect from plugs of a wire of system of ignition, in particular the multicontact plug of the control device of the engine.

Each electric chain of high voltage has to be loaded with the resistor having resistance not less than 2 kOhm i.e. at inclusion of ignition contact tips of spark plugs have to be built in.

Only at the disconnected ignition attach and disconnect from plugs of wires measuring devices (the tachometer / device for check of system of ignition).

On plugs 1 (–) and 15 (+) coils of ignition it is impossible to connect a control bulb.

If when servicing the car carrying out test of flammable sparks is required, then it needs to be done only with use of a spark plug directly in the cylinder. At the same time provide good contact of a spark plug with the car case. You hold a contact tip of a spark plug or a wire of high voltage not with a hand, and well isolated pincers in relation to the car case (for example, to the block of cylinders of the engine).

Before determination of frequency of rotation of a starter check compression pressure, switch off ignition and remove the plug (A) on the HFM control device or the position sensor of a bent shaft (L5) on the PMS control device.

Connecting elements of primary chain carry out tension to 400 Volts! Therefore it is always necessary to connect core clips / package of the car case.

At electro-and spot welding disconnect electric onboard network from the plug of the rechargeable battery.

Wash the engine only at the switched-off ignition.

Persons with an electrostimulator of heart cannot work with electronic system of ignition.