Mercedes S-Class W-140

1991-1999 of release

Repair and car operation

Diagnostics of malfunctions

The description of diagnostics of electronic control systems and diagnostic codes are provided in Head engine Electric equipment.

In this Section the simplest scheme of clarification of the reasons of malfunctions and the refusals occurring in knots and systems of a vehicle is offered. Refusals and their possible reasons are broken into groups on the basis of the relation to certain components or car systems, such as the engine, cooling system, etc., besides, in the text references to Chapters and Sections concerning these problems are given.

Remember that the successful conclusion of search of causes of defect at all is not the black magic available to only skilled professional mechanics, and is defined by a combination of a certain knowledge and a patient, systematic approach to problem research. To move always follows from simple to difficult, to lead up each check to the logic end and to try not to pass the obvious facts - everyone can forget to fill fuel in a fuel tank or to leave for the night included lighting devices.

And at last, always it is necessary to try to make an accurate picture of development of malfunction and to undertake the corresponding steps on recurrence prevention. If refusal of electric equipment was the result of violation of quality of contact, check at the same time a condition of all other contacts and electric sockets of system. If the same safety lock several times in a row continues to fuse, there is no sense in its further replacement - it is necessary to try to find out a cause of failure. Remember that failure of a minor component can be a sign of violation of functioning of more important knot or the whole system.

The engine is not turned in attempts of its start

1. Corrosion of plugs of the battery takes place or weakened fastening of tips of wires on them. Check a condition of plugs and tips. Tighten terminal clips, if necessary remove corrosion traces.
2. The battery is discharged or faulty. If tips of wires are found pure and reliably fixed on battery plugs, turn the ignition key in the situation ON, then include head headlights and/or windscreen cleaners. If this electric equipment does not function, the battery is discharged.
3. Transmission it is inexact it is established in the situation "R".
4. Conducting in a chain of system of start is torn off or weakened fastening of wires on plugs. Check a condition роводов, plugs and electric sockets of the battery, the traction relay of a starter and the ignition lock.
5. The gear wheel of a starter is jammed in a gear wreath of a driving disk. Try to turn the engine for a crankshaft pulley. At the first possibility remove a starter and check a condition of a gear wheel and a gear wreath.
6. The traction relay of a starter (is faulty see. Head engine Electric equipment).
7. The starter (is faulty see. Head engine Electric equipment).
8. The ignition lock is faulty.

The engine is turned, but not started

Petrol models

1. Start (see appropriate section of Head the Operation manual) is incorrectly made.

Order of start of the petrol engine

Stability of operation of the engine on single turns is broken

Petrol models

1. Depression losses take place. Make sure of reliability of an inhaling of fixing bolts/nuts, check the fact and quality of fastening on the unions on the inlet pipeline of all vacuum hoses. Hear to the working engine by means of a stethoscope or a piece of a fuel hose. Existence of a hissing sound will allow to reveal a source of "leakage" of vacuum. It is possible to use for check by solution of soap water not less effectively.
2. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
3. The valve of system of operated ventilation of a case (is blocked see. Head Engine).
4. The air filter (is blocked see. Head of the Power supply system and release).
5. The fuel pump does not provide giving of enough of fuel to injectors of system of injection (see. Head of the Power supply system and release).
6. Leaks through laying of a head of cylinders take place. Make measurement of kompressionny pressure in engine cylinders.
7. Working ledges of cams of a camshaft (are worn-out see. Head Engine).

Diesel models

1. Quality of connections of fuel hoses on TNVD and the fuel filter is broken. Replace fuel hoses, fix them collars, tighten screws of angular connections.
2. TNVD fastening is mechanically damaged or weakened. Check fastening.
3. Are mixed by junctions of the returnable pipeline and the pipeline of supply of fuel. Connections put on the places. The screw of connection of the returnable pipeline has «OUT» marking.
4. Damage to the line of supply of fuel takes place:
      a) Pipelines or hoses are mechanically damaged or littered, - clear fuel pipelines;
      b) The fuel filter is littered. Replace filtering element.
      c) In the winter it is necessary to check the filter and pipelines on ice or wax existence, - tire out the car in heated garage, add in gasoline system;
      d) Ventilation of a tank or the mesh filter of a toplivozabornik is littered, - clean.
5. Adjustment of the beginning of supply of fuel is brought down. Check, make adjustment.
6. Nozzles are faulty. Check. Unscrew consistently cap nuts - at an otvorachivaniye of a nut of the faulty cylinder turns of the engine will not fall.
7. The fuel pump of a high pressure (TNVD) is faulty. Establish for check new, or obviously serviceable TNVD.

Ignition admissions on single turns take place

1. Spark plugs are worn-out or polluted or the candle gap (is incorrectly exposed see. Head engine Electric equipment).
2. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
3. Wires of spark plugs (are faulty see. Head engine Electric equipment).
4. Bad quality fuel is filled. The fuel filter is hammered.
5. Depression losses in the inlet pipeline or through shlangovy connections take place.
6. There is not enough, or kompressionny pressure in cylinders is non-uniformly distributed. Make compression measurement (see. Head Engine).
7. Violations in work of a control system as the engine take place.

Ignition admissions take place during movement on transfer

1. The fuel filter is blocked or power supply system pollution (takes place see. Head of the Power supply system and release).
2. Spark plugs are faulty or polluted or the candle gap (is incorrectly exposed see. Head engine Electric equipment).
3. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
4. Defect of candle wires (takes place see. Head engine Electric equipment).
5. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
6. Insufficiently or kompressionny pressure is non-uniformly distributed between cylinders. Remove spark plugs and make measurement of kompressionny pressure (see. Head Engine).
7. The ignition system (is faulty see. Head engine Electric equipment).
8. Depression losses on the throttle case, the inlet pipeline or through vacuum hoses take place.

Engine spontaneously глохнет

1. Adjustment of turns of idling is broken.
2. The fuel filter is blocked and/or moisture or dirt got to a power supply system (see. Head of the Power supply system and release).
3. Refusal of components of a power supply system or sensors (takes place see. Head of the Power supply system and release).
4. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
5. Spark plugs are faulty or polluted or the candle gap (is incorrectly exposed see. Head Routine maintenance). Also check a condition of candle wires (see. Head engine Electric equipment).
6. Depression losses on the case of a throttle or through vacuum hoses take place.

The engine does not develop full capacity

1. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
2. The air purifier is littered. To clean or replace.
3. Spark plugs are faulty or the candle gap (is incorrectly exposed see. Head Routine maintenance
4. The ignition coil (is faulty see. Head engine Electric equipment).
5. There does not correspond to requirements AT liquid level (see. Heads Routine maintenance and Avtomaticheckaya transmission).
6. Transmission (revolves see. Head Coupling).
7. The fuel filter is blocked and/or dirt/moisture got to a power supply system (see. Head of the Power supply system and release).
8. Fuel not that grade is filled. Fill in in a tank fuel with the demanded octane number.
9. The adjusting valve of a turbokompressor is damaged
10. The activator of a camshaft of shift of phases GRM is faulty
11. Insufficient or non-uniform on cylinders kompressionny pressure. Make the compression measurement which analysis of results allows to reveal existence of leakages of valves and/or violation of tightness of laying of a head of cylinders (see. Head Engine).

In addition for the diesel engine

1. The air purifier is littered. Clean or replace.
2. Non-uniform supply of TNVD fuel on cylinders. Adjust on the heated-up engine.
3. The moment of the beginning of supply of TNVD fuel is incorrectly established. Establish.
4. The fuel filter or TNVD (nozzle) is littered. Wash out the preliminary filter, replace an element of the filter of thin cleaning, clean a spray or replace the pump (nozzle).
5. Adjustment of the maximum frequency of rotation of a cranked shaft is broken.

There are cottons in system of an admission or shots in release system

1. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
2. Defect in a secondary contour of system of ignition (destruction of insulators of spark plugs or defects of candle wires) (takes place see. Head engine Electric equipment).
3. The system of injection of fuel or its components needs adjustment are excessively worn-out (see. Head of the Power supply system and release).
4. Depression losses on the throttle case, the inlet pipeline or through vacuum hoses take place.
5. Valves (are jammed see. Head Engine).
6. The order of connection of candle wires (is broken see. Head engine Electric equipment).

At movement with acceleration or uphill there are detonation sounds

1. Bad quality fuel is filled.
2. Malfunction of components of a power supply system or electric equipment (takes place see. Heads of the Power supply system and release and engine Electric equipment).
3. Spark plugs not that type are established. Check candles and coils on existence of damages (see. Head engine Electric equipment).
4. Base installations of the block of electronic control are broken.
5. The detonation sensor is faulty.
6. Depression losses take place.

Kalilny ignition (the engine continues to work after ignition switching off) takes place

1. Idling turns (are excessively high see. Head Engine).
2. Malfunction of components of a power supply system or electric equipment (takes place see. Head engine Electric equipment).
3. The valve of a purge of an adsorber of system of catching паров fuels (EVAP) is damaged.
4. The working temperature of the engine is excessive. The possible reasons of this violation can be decrease in level of cooling liquid (see. The head of System of cooling, heating), failure of the thermostat, blocking of a radiator or malfunction of the water pump (see. Head of System of cooling, heating).

The diesel engine smokes

1. Black smoke:
      a) The air purifier is polluted, - wash out and fill with fresh oil or replace an element;
      b) Inappropriate fuel is applied, - wash out a tank and replace fuel;
      c) The moment of the beginning of giving of TNVD is incorrectly established.
2. Dark blue smoke:
      a) Oil burning in the combustion chamber owing to wear of piston rings, high level of oil in an air purifier, wear of epiploons in covers of a turbokompressor, formation of thinnesses in laying between a block case and a turbokompressor, - repair the engine, establish normal level of oil, replace epiploons, tighten bolts of fastening of a turbokompressor or replace laying;
      b) Fuel to one of nozzles does not move, - check on heating of final branch pipes of a collector;
      c) Bad dispersion of fuel by a nozzle because of malfunction of the valve or spray break, - grind in the valve or replace a nozzle.
3. White or brown smoke:
      a) Low temperature in cooling system, - check the thermostat;
      b) Bad work of nozzles owing to wear or spray break, - replace a spray.

Engine electric equipment

The battery does not "hold" a charge

1. The driving belt of the generator is worn-out or damaged, or adjustment of its tension (is broken see. Head engine Electric equipment).
2. Level of electrolit is insufficient or the battery (is strongly discharged see. Head engine Electric equipment).
3. Corrosion of plugs of the battery takes place or weakened fastening of tips of wires on them (see. Head engine Electric equipment).
4. The generator does not provide a demanded current of a charge (see. Head engine Electric equipment).
5. Electroconducting of a charging contour is torn off or is in any other manner damaged or weakened fastening of wires on plugs (see. Head engine Electric equipment).
6. Short circuit of electroconducting creates continuous leakage of a current developed by the battery on "weight" (address to Head Electric equipment of the engine and to Schematic diagrams of electric equipment).
7. Internal defect of the battery takes place.

The control lamp of a charging does not die away at increase in turns

1. The driving belt is weakened. Check a natyazhitel of a maple belt.
2. Damage of the obgonny coupling (only turbodiesel). Remove the generator and turn a power shaft of the generator to the left. If the working surface of a pulley does not rotate, damage, as a rule, in the obgonny coupling.
3. Damage of a regulator of the tension/generator. Disconnect a wire (D +) from a reverse side of the generator and include ignition. If now the control lamp does not light up, malfunction, as a rule, in a regulator of tension or in the generator.
4. Wear of brushes. Visually check brushes, if necessary replace.
5. Regulator damage. Check, if necessary replace.
6. Generator damage. Check, if necessary replace.
7. Wire damage between the generator and a tension regulator.
8. Damage of the block of the dashboard.

The control lamp of a charging does not light up at ignition key turn in the situation ON (at ignition inclusion)

1. Fused or otherwise the control lamp on the dashboard (failed see. Head Onboard electric equipment).
2. The generator (is faulty see. Head engine Electric equipment).
3. Defect of the printed-circuit board, conducting in the block of a control panel or the boss of a lamp (takes place see. Head Onboard electric equipment).

The control lamp of a charge burns after ignition switching off

Starter

1. If the starter is not turned, at first it is necessary to check, that on the plug 50 traction relays at least 10 V.Esli's necessary tension tension was lower than this value, it is necessary to check the wires entering into a contour of a current of a starter according to the scheme.
Whether
2. works a starter at full tension of the battery, it is possible to check as follows:
      а) Not including transfers, include ignition;
      b) To Peremknita of the starter plug 30 and 50 a wire of section at least 4 mm2, address also to the Section «Check of the traction relay» of Head engine Electric equipment).
3. If the starter works faultlessly, the cause of defect should be looked for in wires to a starter. If the starter does not earn, it should be checked in the removed condition.

Check condition:

In places of connection of a wire should be well fixed and should not be oxidized.

The starter does not rotate at turning on of the lock of ignition

1. The battery is discharged. Charge the battery.
2. To Peremknita of the starter plug 30 and 50: The starter rotates. Break of a wire 50 to the ignition lock, is faulty the starter switch. Eliminate break, replace defective details.
3. Break of a cable or the weight socket, the battery it is discharged. Check cables and battery sockets, measure tension of the battery, if necessary charge.
4. Insufficient passing of a current owing to the weakened or oxidized sockets. Clear poles and battery plugs, check connections between the battery, a starter and weight.
5. There is no tension on the plug 50 traction relays. Wire break, the switch of a starter is faulty.

The starter rotates slowly and does not turn the crankshaft

1. Battery category. Charge the battery.
2. Summer oil is filled in. Fill in all-weather oil.
3. Insufficient passing of a current owing to the weakened or oxidized sockets. Clear poles and battery plugs, check connections between the battery, a starter and weight.
4. Coal brushes do not adjoin to a collector, jam in directing, are worn-out, broken, greasy or polluted. Check brushes, clear or replace. Check the directing.
5. Insufficient distance between brushes and a collector. Replace brushes and clear directing brushes.
6. The collector in grooves or scorched and was made oily. Process a collector or replace an anchor.
7. There is no tension on the plug 50 (min 8 B). Check the switch of a starter or the traction relay.
8. The bearing is broken. Check the bearing, if necessary replace.
9. The traction relay is faulty. Replace the traction relay.

The starter seizes and rotates the engine breakthroughs

1. The gear wheel drive is faulty. Replace a gear wheel drive.
2. The gear wheel is polluted. Clear a gear wheel.
3. The gear wreath of a flywheel is faulty. Process a gear wreath if it is required, replace a flywheel.

The gear wheel of a starter does not depart from a wreath

1. The drive of a gear wheel or carving are polluted or damaged. Clear or replace a gear wheel drive.
2. The traction relay is faulty. Replace the traction relay.
3. The returnable spring weakened or became torn. Replace a returnable spring.

The starter continues to work after an ignition key otpuskaniye

1. The traction relay jammed, is not disconnected. At once switch off ignition, replace the traction relay.
2. The ignition lock is not disconnected. At once disconnect the battery, replace the ignition lock.

Power supply system

Fuel consumption is excessive

Petrol models

1. The element of the air filter (is polluted or blocked see. Head of the Power supply system and release).
2. Malfunction of components of a power supply system, electric equipment or electronic control (takes place see. Heads of the Power supply system and release and engine Electric equipment).
3. Leaks in system of an admission of air.
4. Damages of system of release / catalytic converter.
5. Pressure in tires does not suffice or tires not are established that size.

Diesel engine

1. Contamination of the returnable pipeline. Blow air the returnable pipeline from TNVD to a fuel tank.
2. Too high turns of idling and maximum turns. Adjust.
3. The engine has mechanical damages. Check a compression, if necessary repair the engine.

Leakages of fuel take place and/or there is a gasoline smell

1. There are leaks in lines of supply of fuel or ventilating lines (see. Head of the Power supply system and release).
2. The fuel tank is overflowed. Filling make only before automatic shutdown of the gun.
3. Leaks or evaporations from lines of a power supply system and decrease in toxicity of the fulfilled gases (take place see. Head of the Power supply system and release).

The engine is not started

1. At starter inclusion the electric fuel pump does not work (is not audible noise from work). Slightly knock on the pump case to release jammed detail. Check, whether tension is put to the pump. Check serviceability of a safety lock. Check electric contacts on good conductivity.
2. The relay of the fuel pump is faulty. Check the relay.
3. Worked the emergency switch of supply of fuel under a seat of the driver. Drown the switch button.
4. Zalipli valves of injectors. Check injectors, if necessary replace. Check tension giving on injectors. For this purpose расстыкуйте socket of injectors. Attach a diode control lamp to a wire and include a starter. The control lamp should blink.
5. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid. Check electric wires. Poll memory of malfunctions.
6. Fuel pipelines are damaged, littered or are not tight, there are defects of hoses.
7. The fuel filter is littered.
8. The inlet system is not tight. Подсасывается additional air.
9. Vacuum pipelines are damaged or are not tight.
10. The pressure regulator is damaged. Check residual pressure.
11. The sensor of provision of a butterfly valve is damaged.
12. There is no food of the block of electronic control by the engine.
13. Ice or wax existence in the filter or pipelines of the diesel engine.
14. Ventilation of a fuel tank is hammered, the filter in a tank is littered.
15. Preheat does not work.
16. The valve of an otsechka of fuel of the diesel engine is damaged.
17. The moment of the beginning of supply of fuel is brought down.
18. Nozzles of the diesel engine are damaged. Unscrew in turn cap nuts and check, whether the corresponding cylinder works.
19. TNVD is faulty.

The cold engine is started badly, works unstably

1. The contents WITH does not correspond to requirements. Check the contents WITH and idling.
2. The sensor of temperature of cooling liquid / soaked-up air is faulty. Check the sensor.
3. Pressure of fuel does not correspond to demanded value. Check pressure of fuel.
4. The inlet system is not tight. Подсасывается additional air.

The warm engine is started badly, works unstably

1. The system of an admission of air is not tight. Check inlet system. For this purpose leave the engine to idle and cover places of consolidations and connection on an inlet path with gasoline. If the number of turns increases by short time, eliminate not tight places.

2. The return valve of the fuel pump is damaged.
3. Leaks in fuel system.
4. Fuel elevated pressure in a power supply system.
5. Malfunction of system of catching паров fuels.
6. It is hammered or crumpled returnable топливопровод to a tank.
7. Zalipli valves of injectors. Check injectors, if necessary replace. Check tension giving on injectors. For this purpose расстыкуйте socket of injectors. Attach a diode control lamp to a wire and include a starter. The control lamp should blink.
8. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid. Check electric wires. Poll memory of malfunctions.
9. The inlet system is not tight. Подсасывается additional air.
10. Vacuum pipelines are damaged or are not tight.
11. The pressure regulator is damaged. Check residual pressure.
12. The sensor of provision of a butterfly valve is damaged.
13. There is no food of the block of electronic control by the engine.

The engine works with interruptions

1. Electric connections to the fuel pump interrupt from time to time. Check a condition of shtekerny connections and sockets of electric wires of the fuel pump, a measuring instrument of a stream of air and the relay of the fuel pump. Check a safety lock and places of contacts on the relay of the fuel pump. Clear contacts, if necessary replace.
2. Poor quality of fuel, formation of steam jams. Fill qualitative fuel.
3. Too low volume of supply of fuel. Check productivity of the pump.
4. The fuel filter is faulty. Replace the fuel filter.
5. The fuel pump is faulty. Check the fuel pump.
6. Injectors are faulty. Check injectors.
7. It is faulty a lambda probe, violations in a chain of quality management of a mix or there is no heating a lambda probe.
8. The sensor of provisions of a butterfly valve is faulty. Check the sensor of provisions of a butterfly valve.
9. The final collector or reception pipe of system of release (there are leakages of exhaust gases) is damaged.
10. Malfunction of system of catching паров fuels.
11. Weakened fastening of fuel hoses to TNVD and the fuel filter of the diesel engine.
12. At connection submitting and returnable TNVD pipelines are mixed by places.
13. Zalipli valves of injectors. Check injectors, if necessary replace. Check tension giving on injectors. For this purpose расстыкуйте socket of injectors. Attach a diode control lamp to a wire and include a starter. The control lamp should blink.
14. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid. Check electric wires. Poll memory of malfunctions.
15. The inlet system is not tight. Подсасывается additional air.
16. Vacuum pipelines are damaged or are not tight.
17. The pressure regulator is damaged. Check residual pressure.
18. The sensor of provision of a butterfly valve is damaged.
19. There is no food of the block of electronic control by the engine.

The engine works with interruptions at transitional modes and in an idling mode

1. The system of an admission of air is not tight. Check connections of inlet system. Start the engine and grease with gasoline of a place of contact and connection in a soaking-up path. If engine turns quickly increase, eliminate a leakage.
2. Idling adjustment is incorrect. Check an idling regulator, the sensor of provisions of a butterfly valve, a lambda adjustment.
3. The sensor of full loading is faulty or incorrectly adjusted. Check the butterfly valve sensor.

The hot engine is not started

1. Incorrect adjustment of the contents WITH. Check the contents WITH and idling.
2. Too high pressure in fuel system. Check pressure of fuel, if necessary replace a pressure regulator.
3. The returnable pipeline between a regulator of pressure and a fuel tank is littered or will bend. Clean or replace the pipeline.
4. The sensor of temperature of the engine is faulty. Check the temperature sensor.
5. The power supply system is not tight. Make visual survey of all connections in the field of the engine and the electric fuel pump. Tighten all connections.
6. The system of an admission of air is not tight. Check all connections of inlet system.

The engine works after switching off

1. Injectors are not tight. Check injectors.
2. The valve of an otsechka of fuel does not work at the diesel engine.

Greasing system

The control lamp does not burn after ignition inclusion

1. The sensor of pressure of oil is faulty. Include ignition, disconnect a wire from the sensor of pressure of oil and close on "weight". If the lamp lights up, replace the sensor.
2. On the sensor tension, contacts коррозированы does not move. Check electric wires and contacts.
3. The control lamp is faulty. Replace a control lamp.
4. The monitor is faulty. Replace a monitor.

The control lamp does not die away after engine start

The control lamp does not die away after supply of gas or lights up during movement

1. Pressure of oil the too low. Check oil level, if necessary add. Check pressure of oil.
2. The wire to the sensor of pressure of oil has short circuit on "weight". Disconnect a cable from the sensor and take aside (without closing on "weight"), include ignition. If the lamp lights up, check a wire.
3. The sensor of pressure of oil is faulty. Replace the sensor.

Too low pressure of oil on all turns

1. In the engine there is not enough oil. Add oil.
2. The mesh filter is littered. Remove the case pallet, clear the mesh filter.
3. The oil pump is worn-out. Remove the oil pump and check it, if necessary replace.
4. Damages of bearings. Remove the engine.

Too low pressure of oil on small turns

Too high pressure of oil at frequency of rotation of the engine of 2000 rpm

Cooling system

Overheat

1. Insufficiently cooling liquid in system (see. Head of System of cooling, heating).
2. The driving belt of the water pump is worn-out or damaged or adjustment of its tension (is broken see. Heads Routine maintenance and Engine).
3. Internal channels of a radiator are blocked or is polluted the front grille ((is blocked) see. Head of System of cooling, heating).
4. The thermostat (is faulty see. Head of System of cooling, heating).
5. Fan blades (are broken or burst see. Head of System of cooling, heating).
6. The fan sensor switch is faulty.

   At short circuit of red and yellow and red-white wires of the sensor the fan should earn on a half of speed.

7. The index of temperature of cooling liquid is faulty. Check the sensor.
8. The water pump is faulty. Remove and check the pump.
9. Does not hold pressure a radiator cover. Make cover check under pressure.

Overcooling

1. The thermostat (is faulty see. Head of System of cooling, heating).
2. Indications of a measuring instrument of temperature are inexact.

External leakages of cooling liquid

1. Hoses are damaged or destroyed as a result of material aging or weakened fastening them on unions. Replace hoses and/or tighten collars of their fastening (see. Head of System of cooling, heating).
2. Epiploons of the water pump are spoiled. In this case cooling liquid will exude through a control opening in the pump case (see. Head of System of cooling, heating).
3. Leaks from internal channels of a radiator or the lateral tank (ов) take place. Radiator repair is required.
4. Leaks through a drain stopper of the engine (take place see. Head the Engine) or vyzhimny jams of water galleries (see. Head of System of cooling, heating).

Internal leakages of cooling liquid

1. Leaks through laying of a head of cylinders take place. Make check of system of cooling by pressure.
2. There are cracks on walls of cylinders or in head molding. For check disassemble the engine (see. Head Engine).

There are losses of cooling liquid

1. In system cooling liquid (is filled too much see. Head of System of cooling, heating).
2. Cooling liquid boils away as a result of an engine overheat.
3. Internal or external leakages of cooling liquid take place.
4. The radiator cover is faulty. Check a cover pressure.

Circulation of cooling liquid is broken

1. The water pump does not function properly. It is simplest to make sure of functioning of the pump having pressed the top hose of a radiator at the engine working at single turns. If at an otpuskaniye of a hose the liquid push in it is felt, the pump functions regularly (see. Head of System of cooling, heating).
2. Passableness of system of cooling is broken. Merge cooling liquid, wash out system and fill it with a fresh mix (see. Head of System of cooling, heating). If there is such need, remove a radiator (see. The head of System of cooling, heating) also carry out its obratnopotochny washing.
3. The driving belt of the water pump is worn-out or damaged or adjustment of its tension (is broken see. Heads Routine maintenance and Engine).
4. The thermostat (is jammed see. Head of System of cooling, heating).

Heater

The fan of a heater does not work

1. The safety lock of the motor of the fan is faulty. Check a fan safety lock, if necessary replace.
2. the fan switch is faulty. Check, whether tension is put to preresistors, remove and check the fan switch.
3. The electromotor is faulty. Check, whether tension is put to contacts of the motor of the fan at the included ignition and the closed switch of the fan. If tension is put, replace the motor.

The fan of a heater does not work at one of steps

The heater is not switched off by a regulator

1. The switch is faulty. Check the switch.
2. Cables of an adjusting mixing zaslonka are damaged or badly mobile. Replace cables.

Too low capacity of heating

1. Too low level of cooling liquid. Check level of cooling liquid, if necessary add.
2. The control unit of a heater has a heavy course, is faulty. Check the heater control unit, if necessary replace a cable.

Noise in the field of the heater fan

1. Dirt, leaves got. Remove the fan and clean it, clear the air channel.
2. Disbalance of a krylchatka, malfunction of the bearing. Remove the fan motor, check ease of a course.

Automatic transmission (AT)

The common problems connected with functioning of the mechanism of switching

1. It is possible to carry the following to number of the refusals connected with violation of adjustment of draft of switching:
      a) Start of the engine is possible at provisions of transmission, distinct from "R" (Parking) and «N» (Neutral);
      b) Indications of the indicator of provision of transmission differ from really chosen transfer;
      c) The car moves at the transmission established in the situation "R" or "N";
      d) Transfers are switched hardly or any way.
2. Make adjustment of draft of gear shifting (see. Head gear shifting Box).

Transmission revolves, is switched hardly, publishes extraneous noise or does not provide car movement at installation on one of lobbies or a reverse gear

1. There is a set of the possible reasons of the problems listed in heading, however under competence of the amateur mechanic one of them - the wrong level of transmission liquid gets only.
2. Before driving away the car in a workshop of car-care center check level and a condition of transmission liquid (see. Head Routine maintenance). Modify level according to requirements of Specifications) or replace liquid together with the filter. If the situation was not corrected, address for the help to experts.

Leakages of transmission liquid take place

1. AT liquid has dark red color. Traces of its leaks should not be confused to traces of impellent oil which can be demolished on a case of transmission by a running stream of air.
2. For identification and localization of a source of leak first of all remove from a transmission boat all traces of dirt and greasing. Use a suitable obezzhirivatel and/or make steam cleaning. Then make on the car a short trip on small speed (that traces of leak did not communicate a running stream far from its source). Stop, поддомкратьте the car and by visual survey establish a leak source. More often as those act:
   
      a) The pallet of a case of transmission, - tighten fixing bolts and/or replace pallet laying;
      b) A tube of filling of liquid, - replace rubber consolidation in a place of an entrance of a tube in a transmission case;
      c) Lines of transmission liquid, - tighten shtutserny connections or replace lines;
      d) The ventilating tube, - transmission is overflowed and/or water got to it.

Oil has brown color or smells as ashes

Low level of liquid in a box (see. Head Routine maintenance).

The kickdown mode does not join by full pressing a pedal (the low gear does not join)

1. Low level of liquid in a box (see. Section of Head Routine maintenance).
2. Malfunction in a control system of the engine (see. A power supply system and injection of fuel of the petrol engine - the general information and System of injection of fuel of the diesel engine - the general information of Head of the Power supply system and release).
3. Malfunction of the sensor or its conducting (see. Automatic transmission of 722.6 Heads Avtomaticheckaya transmission).
4. Adjustment of a cable of the selector (is broken see. Automatic transmission of 722.6 Heads Avtomaticheckaya transmission).

The engine is not started at any position of the selector or started in any situation except "R" and «R»

1. Adjustment of the sensor of permission of start (is broken see. Automatic transmission of 722.6 Heads Avtomaticheckaya transmission).
2. Malfunction in a control system of the engine (see. A power supply system and injection of fuel of the petrol engine - the general information and System of injection of fuel of the diesel engine - the general information of Head of the Power supply system and release).
3. Adjustment of a cable of the selector (is broken see. Automatic transmission of 722.6 Heads Avtomaticheckaya transmission).

Transmission revolves, breakthroughs or noise at gear shifting. The car does not move at inclusion of modes D or R

1. Low level of liquid in transmission (see. Head Routine maintenance).
2. Malfunction of the sensor or its conducting (see. Automatic transmission of 722.6 Heads Avtomaticheckaya transmission).
3. Malfunction in a control system of the engine (see. A power supply system and injection of fuel of the petrol engine - the general information and System of injection of fuel of the diesel engine - the general information of Head of the Power supply system and release).

Bridges

Extraneous noise

1. Usual road noise. To adjustment do not give in.
2. Noise of tires. Check a condition of protectors and pressure of a rating of tires.
3. Bearings of wheels are worn-out or damaged, or weakened effort of their tightening.

Vibrations

Leakages of oil

Brake system

The increased course of a pedal of a brake

The pedal of a brake springs and fails

1. Air in brake system. Remove air from system.
2. There is not enough liquid in the tank. Add new brake liquid, remove from system air.
3. Formation of vials of steam. It is shown, mainly, at big load of brakes. Replace brake liquid, remove air from system.

Decrease in effect of braking, pedal fails

1. Pipeline leakage. Tighten connections of the pipeline or replace tubes.
2. Damage of cuffs to the main thing or working brake cylinders. Replace a cuff. In the main brake cylinder replace internal elements, if necessary replace the main cylinder.
3. Rubber laying is damaged. Repair a support.

Bad braking despite big effort of pressing of a pedal

1. Brake slips are greasy. Replace brake shoes.
2. The improper or hardened blocks are established. Replace blocks. Establish original blocks of Mercedes-Benz.
3. The brake amplifier is faulty. Check the brake amplifier.
4. Brake shoes are worn-out. Replace brake shoes.

When braking the car withdraws aside

1. Pressure in tires does not correspond to the demanded. Check and modify pressure in tires.
2. Non-uniform wear of tires. Replace worn-out tires.
3. Brake shoes are greasy. Replace blocks.
4. On one axis different brake shoes are established. Replace blocks. Establish original blocks of Mercedes-Benz.
5. Bad condition of brake shoes. Replace blocks.
6. Mines of supports are polluted. Clear directing and landing surfaces of blocks in a support.
7. Corrosion of cylinders of brake supports. Replace a support.
8. Non-uniform wear of a brake shoe. Replace brake shoes (on both wheels).

Spontaneous braking

1. The compensatory opening in the main brake cylinder is littered. Clean the main cylinder and replace internal elements.
2. Too small gap between a driving rod and the piston of the main brake cylinder. Check a gap.

Brakes heat up during movement

1. The compensatory opening in the main brake cylinder is littered. Clear the main cylinder and replace internal elements.
2. Too small gap between a driving rod and the piston of the main brake cylinder. Check a gap.
3. The drosseliruyushchy opening in the special valve on the bottom is littered. Clear the main brake cylinder, replace internal elements and brake liquid.

Brakes shiver

1. Blocks of inadequate type are established. Replace blocks, establish original blocks of Mercedes-Benz.
2. Brake disk in places корродирован. Carefully grind a brake disk.
3. The brake disk has lateral palpation. A disk process or replace.

Brake shoes do not depart from a brake disk, the wheel is hardly turned manually

Non-uniform wear of blocks

1. Blocks of inappropriate type are established. Replace blocks, establish original blocks of Mercedes-Benz.
2. The support is polluted. Clear support mine.
3. Heavy piston stroke. Eliminate.
4. The brake system is not tight. Check tightness of brake system.

Wedge-shaped wear of brake shoes

1. The brake disk rotates not parallel to a support. Check surfaces of a prileganiye of a support.
2. Corrosion in supports. Eliminate pollution.
3. The piston works incorrectly. Check position of the piston.

Scratch of brakes

1. Often reason in atmospheric influence (humidity of air). If the scratch appears after long parking at the increased humidity and then vanishes, anything it is not necessary to do.
2. Blocks of inappropriate type are established. Replace blocks, establish original blocks of Mercedes-Benz, cover plates of the basis with protivoskripny (antivizgovy) paste.
3. The brake disk rotates not parallel to a support. Check surfaces of a prileganiye of a brake support.
4. The support mine is polluted. Clear support mine.
5. Pognuta of a spring of fastening of blocks. Replace fastening springs.
6. Press springs are stretched. Replace press springs.

Pulsation of a pedal of a brake

1. ABS in operation. Normally, the help is not required.
2. Too big lateral palpation or the admission on thickness of a brake disk. Check palpation and thickness. Process or replace a disk.
3. The brake disk rotates not parallel to a support. Check a surface of a prileganiye of a support.

The control lamp of ABS lights up during movement

1. Too low voltage of a food (below 10 In). Check tension. Check, whether the control lamp of the generator after engine start dies away. If everything is all right, check maple a belt of a drive of the generator.
2. ABS damage. Check reliability of contact and existence of corrosion of accession of weight at the returnable pump (in the hydraulic block).

Suspension bracket and steering

The car withdraws at movement in one of the parties

1. Tires are pumped non-uniformly up.
2. Defect of tires takes place.
3. Suspension bracket or steering components (are excessively worn-out see. Head Suspension bracket and steering).
4. Carrying out adjustment of corners of installation of forward wheels is required.
5. Forward brake mechanisms (are taken see. Head Brake system).

Breakthroughs, derganye or vibrations take place

1. Balancing of wheels is broken or there was an ovality of disks. Make balancing in a shinomontazhny workshop.
2. Bearings of wheels are worn-out, weakened effort of their tightening or adjustment (is broken see. Head Suspension bracket and steering).
3. Racks shock-absorbers or other components of a suspension bracket (are worn-out or damaged see. Head Suspension bracket and steering).

Excessive rocking car "/zaryvaniye" his nose on turns takes place or when braking

1. Racks shock-absorbers are faulty. Replace all set (see. Head Suspension bracket and steering).
2. Suspension bracket components are damaged. Make check of a condition of components (see. Head Suspension bracket and steering).

Too hardly the steering wheel rotates

1. Excessively liquid level fell in the tank of system of hydrostrengthening of a wheel (see. Head Suspension bracket and steering).
2. Tires are pumped incorrectly up.
3. Hinges of a steering drive (are insufficiently greased see. Head Suspension bracket and steering).
4. Adjustment of corners of installation of forward wheels is broken.
5. The hydraulic booster does not develop the demanded capacity.

Takes place excessive люфт a steering

1. Weakened effort of a tightening of bearings of forward wheels (see. Head Suspension bracket and steering).
2. Suspension bracket or steering components (are excessively worn-out see. Head Suspension bracket and steering).

The system of hydrostrengthening of a wheel does not develop due effort

1. The driving belt of the pump of the hydraulic booster is worn-out or damaged or adjustment of his tension (is broken see. Head Suspension bracket and steering).
2. Excessively liquid level (fell see. Head Suspension bracket and steering).
3. Passableness of hoses or lines of hydraulic system is broken. Check, in case of need make replacements.
4. Air got to hydraulic system. Pump over system (see. Head Suspension bracket and steering).

Excessive wear of protectors (not in one any area) takes place

1. Tires are pumped incorrectly up.
2. Balancing of wheels is broken. Address in a shinomontazhny workshop.
3. Disks of wheels are damaged. Check, in case of need make replacement.
4. Suspension bracket or steering components (are excessively worn-out see. Head Suspension bracket and steering).

Excessive wear of protectors on external edge takes place

1. Tires are pumped incorrectly up.
2. Turns are too sharply made. Reduce speed.
3. Adjustment of corners of installation of forward wheels (excessive convergence) is broken. Address in a workshop for carrying out professional adjustment.
4. Will bend or is braided the suspension bracket lever (see. Head Suspension bracket and steering).

Excessive wear of protectors on internal edge takes place

1. Tires are pumped incorrectly up.
2. Adjustment of corners of installation of forward wheels (divergence) is broken. Make adjustment in a car-care center workshop.
3. Components of a steering are damaged or weakened their fastening (see. Head Suspension bracket and steering).

Local wear of a protector takes place

1. Balancing of wheels is broken.
2. Are damaged or погнуты disks. Check, in case of need make replacement.
3. Defect of tires takes place.

Defects of brushes of a screen wiper

Proskalzyvaniye

1. Elastic bands are polluted. Clear elastic bands a rigid nylon brush and solution of detergent or alcohol.
2. Shabby edges of brushes, elastic bands are worn-out or broken off. Replace elastic bands.
3. The old elastic bands, the cracked surfaces. Replace elastic bands.

In the field of cleaning the water remains gather at once to drops

The brush clears unilaterally - in one party well, in another is not present

1. The elastic band is deformed in one party «does not overturn any more». Establish a new elastic band.
2. The lever of a screen wiper is braided, the brush not precisely adjoins to glass. Carefully turn the lever, vertical situation will not be reached yet.

Crude surfaces

1. The elastic band escaped from a frame. Carefully insert an elastic band into a frame.
2. The brush adjoins to glass non-uniformly as spring levels or plates are bent. Replace a brush. This malfunction first of all appears at negligent installation of a spare brush.
3. Force of pressing by the lever is too small. Slightly grease hinges of levers of a screen wiper and a spring or establish the new lever.

Defects of tires

Strong wear of the tire on both parties of a working surface

Strong wear of the tire in the middle of a working surface on all circle of a protector

Non-uniform wear of a protector

Non-uniform wear in the middle of a protector

Strong wear of separate sites in the middle of a working surface of a protector

Sawtooth wear of a protector, it is frequent together with a rupture of a fabric basis of the tire invisible outside

Rubber uvulas at lateral edges of a protector (scaly wear)

Formation of agnails on one party of a protector of a forward wheel

Ruptures of a cord. At first are visible only from within

Unilateral wear of a working surface of a protector

1. Check disorder adjustment.
2. ABS damage. Check reliability of contact of connection with the case at the returnable pump (in the hydraulics block).