Mercedes M-Class W163

since 1997 of release

Repair and car operation

Diagnostics of malfunctions

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

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.

Engine

If the engine is not started, it is necessary to analyse a situation. Indispensable conditions of start of any petrol engine are serviceability of giving in cylinders of an air and fuel mix and adequacy of an iskroobrazovaniye on spark plugs.

First of all it is necessary to make sure of serviceability of supply of fuel (see. Head of the Power supply system and production of the fulfilled gases).

To define, whether the spark is developed, it is necessary to turn out candles, to insert into tips and separately to put to weight. Thus it is not necessary to hold a wire or a tip hands, - use the isolated flat-nose pliers. Ask the assistant to start the engine. If the spark is absent, try to define a cause of failure (see. Head of System of electric equipment of the engine).

Procedures of diagnostics of an electronic control system and codes of malfunctions are also given in the Head of System of electric equipment of the engine.

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.
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.
5. The gear wheel of a starter is jammed in a gear wreath of a driving disk.
6. The traction relay of a starter is faulty.
7. The starter is faulty.
8. The ignition switch is faulty.

The engine is turned, but not started

Petrol models

1. Start is incorrectly made. Act as follows:

1. Cock the parking brake;
2. Include neutral transfer (RKPP) / transfer the selector lever to the situation "R" or "N" (AT);
3. Without squeezing out a gas pedal, turn a key in the ignition lock to the right against the stop. As soon as the engine will be started, at once release a key. If start of the heated-up engine is not possible to make at a provorachivaniye it a starter more than 4 seconds, it is necessary to squeeze out a gas pedal slowly. Do not turn the engine more than 30 seconds in a row, before repeated attempt wait not less than 15 seconds;
4. At unstable turns (for example, at ignition admissions) in order to avoid failure of the catalytic converter try to turn on the engine only for short time and do not allow strong loadings, - immediately drive away the car on HUNDRED companies Mercedes-Benzs;
5. In areas where the temperature of external air often falls below - 20°С, installation of a heater of cooling liquid is recommended, - the reference on this matter can be received on any HUNDRED Mercedes-Benzs.

2. The engine immobilizator is faulty or is not disconnected.
3. The safety lock of the electric fuel pump or electronic system of injection (is faulty see. Head Onboard electric equipment).
4. The fuel tank is empty, or is filled with poor-quality fuel.
5. The air filter is strongly polluted. Leakages of vacuum in elements of supply of air, malfunction in a control system of injection of fuel and ignition take place.
6. The battery (the engine is turned too slowly) is discharged.
7. Terminal connections of the battery are oxidized, or weakened their fastening.
8. The fuel pump is faulty, or its relay is damaged, - aurally check serviceability of activation of the pump at ignition inclusion.
9. Components of system of ignition are damaged or excessively humidified.
10. Spark plugs are worn-out or faulty, or the candle gap is incorrectly exposed.
11. Electroconducting of system of start is torn off or disconnected, or weakened fastening of wires on plugs.
12. Electroconducting of the coil of ignition is torn off or disconnected, or or weakened fastening of wires on coil plugs.
13. The control unit safety lock is damaged by the engine, is faulty any of sensors: A hall, the pulse sensor, the sensor of temperature of cooling liquid (ECT) or soaked-up air (IAT).
14. Pressure of a compression does not suffice.

Diesel models

1. Start is incorrectly made. Act as follows:

1. Cock the parking brake;
2. Include neutral transfer (RKPP) / transfer the selector lever to the situation "R" or "N" (AT);
3. Turn a key in the ignition lock in situation 2, - on an instrument guard the control lamp of preheat (see appropriate section of Head Governing bodies and receptions of safe operation) should light up. Start of the engine should be carried out not earlier than the control lamp will go out, - without including onboard consumers of the electric power and without squeezing out a gas pedal, turn a key in the lock to the right against the stop. At temperature of external air is lower - 10°С it is necessary to squeeze out also against the stop a gas pedal. Continue to turn the engine a starter until its turns are not stabilized, however no more than 30 seconds. Before restart after unsuccessful attempt do not forget to return at first a key to situation 0 and to wait not less than 15 seconds;
4. Watch the index of pressure of impellent oil (see appropriate section in Head Governing bodies and receptions of safe operation): the indicator of pressure should be activated at once after start. At strong cooling of the engine indication of pressure appears only after a while after start. Do not increase number of turns of the engine, indication of pressure of oil yet is not activated;
5. If the control lamp of preheat does not light up, malfunction in system of preheat which should be immediately eliminated on HUNDRED Mercedes-Benzs takes place;
6. In areas where the temperature of external air often falls below - 20°С, installation of a heater of cooling liquid is recommended. On this matter you can receive the reference on any HUNDRED Mercedes-Benzs.

2. The engine immobilizator is faulty
3. The safety lock of the electric fuel pump or preheat system is faulty.
4. The engine is not heated-up: check serviceability of functioning of the device of preheat.
5. On the electromagnetic locking valve there is no tension. Connect to the switch the voltmeter or a sampler on a light-emitting diode. Include ignition, the light-emitting diode should light up, otherwise it is necessary to find break of electroconducting and to eliminate it.
6. The electromagnetic locking valve is faulty. Check reliability of fastening of the electromagnetic switch, estimate a condition of contacts. Switch on and off ignition, - in the switch click should be distributed.
7. Damage to the line of supply of fuel or air to lines takes place:

1. Pipelines or hoses are mechanically damaged or littered, - clear fuel pipelines and remove air from lines and the filter;
2. The fuel filter is littered, - replace filtering element;
3. 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;
4. Ventilation of a tank or the mesh filter of a toplivozabornik is littered, - clean.

8. Adjustment of the moment of the beginning of supply of fuel is brought down.
9. Nozzles are faulty, - at an otpuskaniye of a shtutserny nut топливопровода a faulty nozzle turns of the engine will not fall.
10. The fuel pump of a high pressure (TNVD) is faulty.
11. Too low pressure of a compression.

The starter functions without an engine provorachivaniye

1. The starter gear wheel is jammed.
2. Teeths of a gear wheel of a starter or flywheel wreath are worn-out or damaged.

Start of the cold engine is complicated

1. It is discharged, or the battery is insufficiently charged.
2. Violation of serviceability of functioning of components of a power supply system, or electric equipment takes place.
3. In the filter of thin cleaning of the diesel engine settled paraffin.
4. Glow plugs of the diesel engine are faulty.

Start of the hot engine is complicated

1. Passableness of the air filter is broken.
2. Violation of serviceability of functioning of components of a power supply system, or electric equipment takes place.
3. Fuel does not arrive to injectors of system of injection.
4. The corner of an advancing of supply of fuel of the diesel engine got off.
5. Pressure of a compression in cylinders does not suffice, TNVD of the diesel engine is faulty, or its adjustment is broken.

Gearing of a starter occurs is too noisy or with difficulty

1. Teeths of a gear wheel of a starter or flywheel wreath are worn-out or damaged.
2. Bolts of fastening of a starter are lost, or weakened effort of their tightening.

The engine is started, but at once глохнет

1. The engine immobilizator is faulty.
2. Electroconducting is faulty, or weakened fastening of wires on coil or generator plugs.
3. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
4. Base installations of the module of management of the engine (ESM) are broken.
5. Has places damage to release system / the catalytic converter.
6. Depression losses through prokladochny surfaces of the inlet pipeline or the block of injection of fuel take place.

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. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
3. Passableness of the valve of system of operated ventilation of a case is broken.
4. Passableness of the air filter is broken.
5. The fuel pump does not provide giving of enough of fuel to injectors of system of injection.
6. Leaks through laying of a head of cylinders take place, - make measurement of kompressionny pressure in engine cylinders (see. Head Engine).
7. Working ledges of cams of a camshaft are worn-out.

Diesel models

1. Quality of connections of fuel hoses on TNVD and the fuel filter is broken.
2. TNVD fastening is mechanically damaged or weakened.
3. Are mixed by junctions of the returnable pipeline and the pipeline of supply of fuel.
4. Damage to the line of supply of fuel takes place:

1. Pipelines or hoses are mechanically damaged or littered, - clear fuel pipelines;
2. The fuel filter is littered. Replace filtering element;
3. 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;
4. 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.
6. Nozzles are faulty, - at an otpuskaniye of a shtutserny nut топливопровода a faulty nozzle 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.
2. Malfunction of components of a power supply system or electric equipment takes place.
3. VV electroconducting is faulty.
4. Poor-quality fuel is filled, or passableness of the fuel filter is broken.
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.
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.
2. Spark plugs are faulty or polluted or the candle gap is incorrectly exposed.
3. Malfunction of components of a power supply system or electric equipment takes place.
4. Defect of VV of electroconducting takes place.
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.
7. The ignition system is faulty.
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. Passableness of the fuel filter is broken, or moisture or dirt got to a power supply system.
3. Refusal of components / information sensors of a power supply system takes place.
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 of the Power supply system and production of the fulfilled gases). Also check a condition of VV of electroconducting.
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.
2. The air purifier is littered.
3. Spark plugs are faulty or the candle gap is incorrectly exposed.
4. The ignition coil is faulty.
5. AT liquid level (fell see. Head of the Power supply system and production of the fulfilled gases).
6. Transmission revolves.
7. The fuel filter is blocked and/or dirt/moisture got to a power supply system.
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 at the corresponding complete set).
10. The activator of a camshaft of shift of phases GRM is faulty.
11. Insufficiently kompressionny pressure, or uniformity of its distribution between cylinders is broken.

In addition for the diesel engine

1. The air purifier is littered.
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.
4. The fuel filter or TNVD (nozzle) is littered.
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. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
2. Defect in a secondary contour of system of ignition (destruction of insulators of spark plugs or damage of VV of electroconducting) takes place.
3. The system of injection of fuel needs adjustment, or its components are excessively worn-out.
4. Depression losses on the throttle case, the inlet pipeline or through vacuum hoses take place.
5. Valves are jammed.
6. The order of connection of VV of electroconducting is broken.

At movement with acceleration or uphill there are detonation sounds

1. Bad quality fuel is filled.
2. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
3. Spark plugs not that type are established.
4. The base ECM installations 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.
2. Malfunction of components of a power supply system or electric equipment takes place.
3. Serviceability of functioning of the valve of a purge of an adsorber of system of catching паров fuels (EVAP) is broken.
4. The working temperature of the engine is excessive. Decrease in level of cooling liquid, failure of the thermostat, blocking of a radiator or malfunction of the water pump can be the possible reasons of this violation.

The exhaust of the diesel engine is filled excessively with smoke

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 of System of electric equipment of the engine).
2. Level of electrolit is insufficient or the battery is strongly discharged.
3. Corrosion of plugs of the battery takes place or weakened fastening of tips of wires on them.
4. The generator does not provide a demanded current of a charge.
5. Electroconducting of a charging contour is torn off or is in any other manner damaged or weakened fastening of wires on plugs.
6. Short circuit of electroconducting creates continuous leakage of a current developed by the battery on "weight".
7. Internal defect of the battery takes place.

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

1. The driving belt is weakened.
2. The obgonny coupling of the hydrotransformer (only a turbodiesel) is damaged. 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. The regulator the tension/generator is damaged. Disconnect a wire (D +) from a reverse side of the generator and include ignition. Further it is necessary to check a condition of a regulator of tension of the generator.
4. Brushes are worn-out.
5. The wire between the generator and a tension regulator is damaged.
6. The combination of devices is faulty.

The control lamp of a charge does not light up at ignition inclusion

1. Fused or otherwise the control lamp on the dashboard failed.
2. The generator is faulty.
3. Defect of the printed-circuit board, conducting in the block of a combination of devices or the boss of a lamp takes place.

The control lamp of a charge does not die away after ignition switching off

1. Diodes are punched.

Starter

If the starter is not turned, at first it is necessary to check, that on the No. plug 50 traction relays were present necessary tension (at least 10 In). At negative results of check it is necessary to estimate a condition of electroconducting of a contour of a current of a starter.

For check of serviceability of operation of a starter at full tension of the battery execute the following actions:

а) Not including transfers, include ignition;
b) To Peremknita of the starter plug 30 and 50 wire section not less than 4 mm ².

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.

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

1. The battery is discharged.
2. To Peremknita of the starter plug 30 and 50: if the starter rotates, check on break a wire 50 to the ignition lock, estimate also a condition the starter switch.
3. The weight wire is torn off, or quality of its terminal connection is broken, the battery is discharged.
4. Weakening of a current owing to violation of quality or oxidation of contact connections.
5. There is no tension on the plug 50 traction relays as a result of electroconducting break, or damage of the switch of a starter.

The starter rotates slowly and does not turn a cranked shaft

1. The battery is discharged.
2. Summer oil is filled in.
3. Insufficient passing of a current owing to the weakened or oxidized sockets.
4. Coal brushes do not adjoin to a collector, jam in directing, are worn-out, broken, greasy or polluted.
5. Insufficient distance between brushes and a collector.
6. The collector in grooves or scorched and was made oily.
7. There is no tension on the plug 50 (at least 8 In).
8. The bearing is broken.
9. The traction relay is faulty.

The starter seizes and rotates the engine breakthroughs

1. The gear wheel drive is faulty.
2. The gear wheel is polluted.
3. The gear wreath of a flywheel is faulty.

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

1. Components of a drive of a gear wheel are polluted or damaged.
2. The traction relay is faulty.
3. The returnable spring weakened or became torn

The starter continues to work after an ignition key otpuskaniye

1. The traction relay is jammed, - immediately switch off ignition and replace the traction relay.
2. The ignition lock is not disconnected, - 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.
2. Malfunction of components of a power supply system, electric equipment or electronic control takes place.
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. Turns of idling and the maximum turns are excessively high.
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. Leaks in lines of supply of fuel or ventilating lines take place.
2. The fuel tank is overflowed. Filling make only before automatic shutdown of the gun.
3. Leaks or evaporations from lines of power supply systems and decrease in toxicity of the fulfilled gases take place.

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 serviceability of giving to the pump tension (check serviceability of a protective safety lock and reliability of fastening of contact plugs of the corresponding electroconducting).
2. The relay of the fuel pump is faulty.
3. Zalipli valves of injectors. Check injectors, if necessary replace. Check tension giving on injectors, - disunite the contact socket of an injector, and connect to a wire a diode lamp sampler and include a starter: the lamp should start to blink.
4. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid. Check a condition of the corresponding electroconducting, poll memory of system of onboard self-diagnostics.
5. Fuel pipelines are damaged, littered or are not tight, there are defects of hoses.
6. The fuel filter is littered.
7. To the inlet highway as a result of tightness violation подсасывается superfluous air.
8. Vacuum pipelines are damaged or are not tight
9. The pressure regulator is damaged, - check residual pressure.
10. The sensor of provision of a butterfly valve is damaged.
11. There is no food of the block of electronic control by the engine.
12. Ice or wax existence in the filter or pipelines of the diesel engine.
13. Ventilation of a fuel tank is hammered, the filter in a tank is littered.
14. Preheat does not work.
15. The valve of an otsechka of fuel of the diesel engine is damaged.
16. The moment of the beginning of supply of fuel is brought down.
17. Nozzles are faulty, - at an otpuskaniye of a shtutserny nut топливопровода a faulty nozzle turns of the engine will not fall.
18. TNVD is faulty.

The cold engine is started badly, works unstably

1. The contents WITH does not correspond to standard requirements, - make the corresponding measurement, check idling turns.
2. The sensor of temperature of cooling liquid (ECT) or soaked-up air (IAT) is faulty.
3. Pressure of fuel does not correspond to demanded value.
4. To the inlet highway as a result of tightness violation подсасывается superfluous air.

The warm engine is badly started, 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, - disunite the contact socket of an injector, and connect to a wire a diode lamp sampler and include a starter: the lamp should start to blink.
8. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid. Check a condition of the corresponding electroconducting, poll system of onboard self-diagnostics.
9. To the inlet highway as a result of tightness violation подсасывается superfluous air.
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.

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.
3. Too low volume of supply of fuel.
4. The fuel filter is faulty.
5. The fuel pump is faulty.
6. Injectors are faulty.
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.
9. The final collector or reception pipe of system of release (there are leakages of the fulfilled gases) is damaged.
10. Malfunction of system of catching паров fuels (EVAP).
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, - disunite the contact socket of an injector, and connect to a wire a diode lamp sampler and include a starter: the lamp should start to blink.
14. There is no signal from the sensor of ignition of the Hall or the sensor of temperature of cooling liquid (ECT). Check electroconducting, poll memory of ECM on existence of codes of malfunctions.
15. To the inlet highway as a result of tightness violation подсасывается superfluous 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 tightness cause of infringement.
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 sensor of provision of a butterfly valve (TPS).

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.
5. Tightness of a power supply system is broken.
6. Tightness of an inlet air path is broken.

The engine works after switching off

1. Injectors are not tight.
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 from the sensor a wire and close it on "weight", - if the lamp lights up, replace the sensor.
2. On the sensor tension, contacts коррозированы does not move, - check a condition of the corresponding electroconducting.
3. The control lamp is faulty.
4. The combination of devices is faulty.

The control lamp does not die away after engine start

Oil перегрето. Fir-trees the control lamp dies away after supply of gas, to do it is required nothing.

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

1. Oil level fell.
2. Short circuit of electroconducting of the sensor of level of oil takes place.
3. The sensor is faulty.

Too low pressure of oil on all turns

1. Oil level fell.
2. The mesh filter of a maslozabornik in the case pallet is littered.
3. The oil pump is worn-out.
4. Bearings of a cranked shaft are damaged

Too low pressure of oil on small turns

The Reduktsionny valve залип abroach because of pollution.

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

The Reduktsionny valve does not open because of pollution.

Cooling system

Overheat

1. Level of cooling liquid fell.
2. The belt of a drive of the water pump is worn-out or damaged or adjustment of its tension is broken.
3. Internal channels of a radiator are blocked or is polluted the front grille (is blocked).
4. The thermostat is faulty.
5. Blades of a krylchatka of the fan are broken or burst.
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.
8. The water pump is faulty.
9. Does not hold pressure a radiator cover, - make cover check under pressure.

Overcooling

1. The thermostat is faulty.
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.
2. Epiploons of the water pump are spoiled, - cooling liquid will exude through a control opening in the pump case.
3. Leaks from internal channels of a radiator or the lateral tank (ов) take place.
4. Leaks through a drain stopper of the engine or vyzhimny jams of water galleries take place.

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.

There are losses of cooling liquid

1. In system the excessive amount of cooling liquid is filled.
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.
2. Passableness of system of cooling is broken. Merge cooling liquid, wash out system and fill it with a fresh mix. If there is such need, remove a radiator and 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.
4. The thermostat is jammed.

Heater

The fan of a heater does not work

1. The safety lock of the electromotor of the fan is faulty.
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 preresistor is faulty.

The heater is not switched off a regulator

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

Too low capacity of heating

1. Level of cooling liquid is insufficient.
2. Handles of management of a heater have a heavy course, is faulty, - check management assembly, if necessary replace the corresponding driving cable.

Noise in the field of the heater fan

1. Dirt, leaves got, - remove the fan and clean it, clear the air channel.
2. Balancing of a krylchatka is broken, is damaged the bearing.

Automatic transmission (AT)

In view of complexity of a design of AT diagnostics of its malfunctions and repair of components is desirable for carrying out in a workshop of car-care center or representation office of the Mercedes-Benz company.

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:

1. Start of the engine is possible at provisions of transmission, distinct from "R" (Parking) and “N” (Neutral);
2. Indications of the indicator of provision of transmission differ from really chosen transfer;
3. The car moves at the transmission established in the situation "R" or "N";
4. Transfers are switched hardly or any way.

2. Make adjustment of draft of gear shifting.

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. 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 the gulf 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

Level of transmission liquid is insufficient.

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

1. ATF level fell.
2. The control system of the engine is faulty.
3. The sensor switch or its electroconducting is faulty.
4. Adjustment of a driving cable of the selector is broken.

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 switch of permission of start is broken.
2. Serviceability of functioning of a control system is broken by the engine.
3. Adjustment of a cable of the selector is broken.

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

1. ATF level fell.
2. The sensor or its electroconducting is faulty.
3. Serviceability of functioning of a control system is broken by the engine.

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

Check a condition of bearings of wheels, serially poddomkrachivy corresponding from corners of the car and rotating a wheel in the manual. Listen thus to sounds starting with the bearing. Remove bearings and check their condition.

Leakages of oil

Epiploons of power shafts are damaged.

Brake system

The increased course of a pedal of a brake

The working contour of a brake path is damaged, - check system on leaks.

The pedal of a brake springs and fails

1. Air got to the brake highway, - pump over system.
2. Liquid level fell in the GTTs tank, - make the corresponding adjustment, pump over system.
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. Tightness of a hydraulic path is broken.
2. Cuffs in the main thing or working brake cylinders are damaged.

Bad braking despite big effort of pressing of a pedal

1. Brake slips are greasy.
2. The improper or hardened blocks are established.
3. The brake amplifier is faulty.
4. Brake shoes are worn-out.

When braking the car withdraws aside

1. Pressure in tires does not correspond to the demanded.
2. Protectors are non-uniformly worn-out.
3. Brake slips are greasy.
4. On one axis different brake shoes are established.
5. Brake shoes are excessively worn-out.
6. Mines of supports are polluted.
7. Supports are damaged by corrosion, - make replacement.
8. Blocks are non-uniformly worn-out.

Spontaneous braking

1. The compensatory opening in the main brake cylinder is littered.
2. The gap between a driving rod and the GTTs piston is insufficient.

Brakes heat up during movement

1. The compensatory opening in the main brake cylinder is littered.
2. The gap between a driving rod and the GTTs piston is insufficient.

Brakes shiver

1. Blocks of inadequate type are established.
2. Brake disk in places корродирован.
3. Palpation of a brake disk is excessively great.

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

Corrosion in cylinders of brake supports. Repair a support, probably replace.

Non-uniform wear of blocks

1. Blocks of inappropriate type are established. Replace blocks, establish original blocks of Mercedes-Benz.
2. Supports are damaged by corrosion, - make replacement.
3. The piston stroke is complicated.
4. Tightness of a path of brake system is broken.

Wedge-shaped wear of brake shoes

1. The brake disk rotates not parallel to a support.
2. Supports are damaged by corrosion, - make replacement.
3. Serviceability of functioning of the piston is broken.

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.
3. The brake disk rotates not parallel to a support.
4. The support mine is polluted.
5. Pognuta of a spring of fastening of blocks.
6. Press springs are stretched.

Pulsation of a pedal of a brake

1. Sign of normal operation of ABS.
2. Palpation of a brake disk is excessively great.
3. The brake disk rotates not parallel to a support.

The control lamp of ABS lights up during movement

1. The supply voltage (below 10 In) does not suffice. 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. Has malfunction of ABS, - check a condition and reliability of fixing of terminal connection of weight of the returnable pump (in the hydromodulator).

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.
4. Carrying out adjustment of corners of installation of forward wheels is required.
5. Forward brake mechanisms are taken.

Breakthroughs, derganye or vibrations take place

1. Balancing of wheels is broken or there was an ovality of disks.
2. Bearings of wheels are worn-out, weakened effort of their tightening or adjustment is broken.
3. Racks shock-absorbers or other components of a suspension bracket are worn-out or damaged.

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

1. Racks shock-absorbers are faulty.
2. Suspension bracket components are damaged.

Too hardly the steering wheel rotates

1. Excessively liquid level fell in the tank of system of hydrostrengthening of a wheel.
2. Tires are pumped incorrectly up.
3. Hinges of a steering drive are insufficiently greased.
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.
2. Suspension bracket or steering components are excessively worn-out.

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.
2. Excessively liquid level fell.
3. Passableness of hoses or lines of hydraulic system is broken.
4. Air got to hydraulic system, - pump over system.

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

1. Tires are pumped incorrectly up.
2. Balancing of wheels is broken.
3. Disks of wheels are damaged.
4. Suspension bracket or steering components are excessively worn-out.

Excessive wear of protectors on external edge takes place

1. Tires are pumped incorrectly up.
2. Turns are too sharply made.
3. Adjustment of corners of installation of forward wheels (excessive convergence) is broken.
4. Will bend or is braided the suspension bracket lever.

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.
3. Components of a steering are damaged or weakened their fastening.

Local wear of a protector takes place

1. Balancing of wheels is broken.
2. Are damaged or погнуты disks.
3. Defect of tires takes place.

Defects of brushes of a screen wiper

Proskalzyvaniye

1. Rubber working elements are polluted.
2. Edges of brushes are shabby, rubber working elements are worn-out or broken off.

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

The windscreen is polluted by varnish polish or oil.

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

1. The rubber working element has unilateral wear.
2. The lever of a screen wiper is braided, the brush not precisely adjoins to glass.

Crude surfaces

1. Reliability of fixing of a working element in a brush frame is broken.
2. The brush adjoins to glass non-uniformly.
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

Too low pressure in tires.

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

Too high pressure in tires.

Non-uniform wear of a protector

Static and dynamic disbalance of a wheel, probably, owing to excessive lateral palpation of a disk, too big люфт in bearing hinges.

Non-uniform wear in the middle of a protector

Static disbalance of a wheel, probably, owing to excessive vertical palpation.

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

Result of sharp braking.

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

Car overload. Check a condition of internal walls of tires.

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

1. Adjustment of corners of installation of wheels is broken.
2. Tires are worn-out.
3. Shock-absorbers / торсионные springs / rack-mount assemblies are faulty.

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

1. Adjustment of a convergence of wheels is broken.
2. Tires are worn-out.
3. Frequent movement on wavy surfaces. Fast movement on turns.

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

Moving through sharp stones, blows of tires, etc. on high speed.

Unilateral wear of a working surface of a protector

1. Check disorder adjustment.
2. Has malfunction of ABS, - check a condition and reliability of fixing of terminal connection of weight of the returnable pump (in the hydromodulator).