Mercedes W124

since 1985-1995 of release

Repair and car operation



W124 Mercedes
+ Governing bodies and control devices
+ MAINTENANCE
+ 2. Maintenance (diesel engines)
+ ENGINE
+ 4. Repair of 6-cylinder petrol SOHC engines
+ 5. Repair of 6-cylinder petrol DOHC engines
+ 6. Repair of the diesel engine established in the car
+ 7. Major maintenance of engines
+ COOLING SYSTEM
+ FUEL SYSTEM
+ 10. System of injection of BOSCH CIS-E fuel (KE-JETRONIC)
+ 11. System of injection of BOSCH HFM fuel
+ 12. Fuel system of diesel engines
+ 13. Fuel system of diesel engines
+ SYSTEMS OF START, IGNITION
+ 15. System of ignition of 4-cylinder petrol engines
- 16. System of ignition of four-cylinder petrol engines
   16.2. General information
   16.3. Check of system of ignition
   16.4. Ignition coil
   16.5. Distributor of ignition and distributor rotor
   16.6. Check and adjustment of a corner of an advancing of ignition
   16.7. Elements of a control system of ignition
+ PRESTARTING HEATING
+ TRANSMISSION
+ 19. Mechanical transmission
+ 20. Automatic transmission
+ POWER SHAFTS
+ BRAKE SYSTEM
+ SUSPENSION BRACKET
+ BODY
+ ELECTRIC EQUIPMENT
+ CHECK OF MALFUNCTIONS






16.7. Elements of a control system of ignition

GENERAL INFORMATION

Prevention

The detachment and removal of sensors of system of ignition can lead to damages which will be written down in memory of the electronic control unit. Some damages which have been written down in memory, can lead to system switching in a special operating mode which can affect working hours of system of ignition. It is desirable to address after any repair of system of ignition on service station to erase from memory of the electronic block, the written-down damages.


SENSOR OF TURNS OF THE CRANKED SHAFT

Removal

PERFORMANCE ORDER
1. Remove a weight wire from the accumulator.
2. Disconnect the electric socket from the sensor of turns of the cranked shaft, located in a motor compartment behind the accumulator.
3. On models with a control system of the HFM engine for improvement of access to the sensor remove a starter from a coupling case.
4. Unscrew a bolt and take the sensor from a coupling case. Remove laying.

Installation

PERFORMANCE ORDER
1. Installation of the sensor of speed of a cranked shaft is made in sequence, return to removal.

SENSOR OF PROVISION OF THE CAMSHAFT

Removal

Arrangement of the sensor of provision of a camshaft

PERFORMANCE ORDER
1. The sensor of provision of a camshaft is established in a forward part of a head of the block of cylinders to the left of a cover of an asterisk of a driving chain (see fig. Arrangement of the sensor of provision of a camshaft). Check that ignition is switched off and disconnect the electric socket from the sensor of provision of a camshaft.
2. Unscrew screws and remove the sensor of provision of a camshaft.
3. Remove a sealing ring and adjusting laying.

Installation

PERFORMANCE ORDER
1. Installation is made in sequence, return to removal. If necessary, establish a new sealing ring and adjusting laying of the demanded thickness.
Prevention

Adjusting laying defines distance from the sensor to a ledge on an asterisk of the camshaft operating inlet valves. If the thickness of adjusting laying less admissible, on an asterisk of a camshaft can strike a ledge on the sensor of provision of a camshaft. For check of a gap uncover heads of the block of cylinders, then turn the engine before ledge combination on a camshaft asterisk with the sensor of provision of a camshaft. Using an edge щупа, check that the gap size between a ledge of an asterisk of a camshaft and the sensor of provision of a camshaft makes 0,4 - 0,6 mm. If necessary adjust gap size, changing thickness of laying under the sensor of provision of a camshaft.


DETONATION SENSORS

Removal

PERFORMANCE ORDER
1. Sensors of a detonation are established on the left side of the block of cylinders of the engine. As sensors have the general plait of wires, they can be removed only assembled.
2. Check that ignition is switched off and disconnect the electric socket of a plait of wires of sensors of a detonation from the control unit.
3. Take a plait of wires of sensors of a detonation from fastening brackets. On models with a control system of the HFM engine for improvement of access remove a starter.
4. Unscrew bolts of fastening and remove detonation sensors from the block of cylinders.

Installation

PERFORMANCE ORDER
1. Installation is made in sequence, return to removal. Tighten bolts of fastening of sensors of a detonation the demanded moment.

ELECTRONIC CONTROL DEVICE

System of ignition of EZL

Removal

Arrangement of the electronic control ECU device of management of system of ignition of EZL

PERFORMANCE ORDER
1. The electronic control device of a control system is established by ignition on the left side of a motor compartment on the top part of an arch of a wheel (see fig. Arrangement of the electronic control ECU device of management of system of ignition of EZL).
2. Remove a weight wire from the accumulator.
3. Disconnect electric sockets of the sensor of provision of a cranked shaft and the detonation sensor. Mark and disconnect two multicontact sockets from the electronic control device.
4. Disconnect a vacuum hose of an inlet collector from the electronic control device and close an opening a stopper.
5. Unscrew nuts and take the electronic control device from a motor compartment.
Prevention

For heat removal improvement from the electronic control device, its bottom surface is covered with special heat-conducting paste.


Installation

PERFORMANCE ORDER
1. Installation is made in sequence, return to removal. If the layer of heat-conducting paste is polluted or hardened, get at the dealer of Mercedes-Benz fresh paste and replace it.

Control system of the HFM engine

Look the relevant information in subsection 11.12.

THE SENSOR OF TEMPERATURE OF COOLING LIQUID

Arrangement of the sensor of temperature of cooling liquid

Usually the system of ignition and system of injection of fuel have one general sensor of temperature of cooling liquid.

SWITCH OF EXTREME PROVISIONS OF THE BUTTERFLY VALVE

The system of ignition and system of injection of fuel cope one general switch of extreme provisions of a butterfly valve. The switch of provision of a butterfly valve can be removed only on the removed case of a throttle. Installation of the switch is necessary for making only at service station.

THE SENSOR OF TEMPERATURE OF AIR ARRIVING IN THE ENGINE

Removal

PERFORMANCE ORDER
1. The sensor of temperature of air arriving in the engine is established sideways a casing of the air filter.
2. Check that ignition is switched off, then disconnect the electric socket from the sensor.
3. Turn the sensor on a quarter of a turn and remove it from a casing of the air filter. Remove laying.

Installation

PERFORMANCE ORDER
1. Installation is made in sequence, return to removal.

SENSOR OF THE TOP DEAD POINT

The sensor of the top dead point is established on an arm over a quencher of krutilny fluctuations from the forward party of the engine. Position of the sensor of the top dead point very important for installation of a corner of an advancing of ignition therefore replacement of the sensor of the top dead point is necessary for making at service station.