Mercedes M-Class W163

since 1997 release

Repair and operation of the car

Diagnostics of malfunctions

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

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

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

And at last, it is always necessary to try to make a clear picture of development of malfunction and to take the corresponding steps for prevention of a recurrence. If the failure of electric equipment happened for a cause of infringement of quality of contact, check a condition of all other contacts and electric sockets of system at the same time. 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 air-fuel mix and adequacy of sparking on spark plugs.

First of all it is necessary to make sure of serviceability of supply of fuel (see the 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 to put separately to weight. At the same time 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 the Head Sistemy of electric equipment of the engine).

Procedures of diagnostics of an electronic control system and codes of malfunctions are also provided in the Head Sistemy 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 fastening of tips of wires on them weakened.
2. The battery is discharged or faulty. If tips of wires are found by pure and reliably fixed on battery plugs, turn the ignition key in position of ON, then include head headlights and/or screenwashes, - if this electric equipment does not function, the battery is discharged.
3. Transmission it is inexact it is established in situation "P".
4. Conducting in a chain of system of start is torn off or fastening of wires on plugs weakened.
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 situation "P" or "N" (AT);
3. Without squeezing out the accelerator pedal, turn a key in the ignition lock to the right against the stop. As soon as the engine is 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 the accelerator 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 admissions of ignition) in order to avoid failure of the catalytic converter try to turn on the engine only for a short time and do not allow strong loadings, - immediately drive away the car on HUNDRED companies Mercedes-Benz;
5. In areas where temperature of external air often falls below -20 °C, 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 the Head Onboard electric equipment).
4. The fuel tank is empty, or is fuelled by low-quality.
5. The air filter is strongly polluted. Leak of vacuum in elements of air supply, malfunction in a control system of injection of fuel and ignition takes place.
6. The battery is discharged (the engine is turned too slowly).
7. Terminal connections of the battery are oxidized, or their fastening weakened.
8. The fuel pump is faulty, or its relay is damaged, - aurally check serviceability of activation of the pump at inclusion of ignition.
9. Components of system of ignition are damaged or excessively moistened.
10. Spark plugs are worn-out or faulty, or the candle gap is incorrectly exposed.
11. The electrical wiring of system of start is torn off or disconnected, or fastening of wires on plugs weakened.
12. The ignition coil electrical wiring is torn off or disconnected, or or fastening of wires on coil plugs weakened.
13. The safety lock of the control unit of the engine is damaged, it is faulty any of sensors: The hall, the pulse sensor, the sensor of temperature of cooling liquid (ECT) or the soaked-up air (IAT).
14. Compression pressure is not enough.

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 situation "P" or "N" (AT);
3. Turn a key in the ignition lock in situation 2, - on an instrument guard the control lamp of preheat has to light up (see appropriate section of the Head Governing bodies and methods of safe operation). Start of the engine should be carried out not earlier than the control lamp goes out, - without including onboard consumers of the electric power and without squeezing out the accelerator pedal, turn a key in the lock to the right against the stop. At a temperature of external air below -10 °C it is also necessary to squeeze out against the stop the accelerator 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. You monitor the index of pressure of motive oil (see appropriate section in the Head Governing bodies and methods of safe operation): the indicator of pressure has to be activated at once after start. At strong cooling of the engine indication of pressure appears after start only after a while. Do not increase engine speed, yet not indication of pressure of oil is not activated;
5. If the control lamp of preheat does not light up, then malfunction in system of preheat which has to be immediately eliminated on HUNDRED Mercedes-Benzs takes place;
6. In areas where temperature of external air often falls below -20 °C, 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 system of preheat 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 has to light up, otherwise it is necessary to find break of an electrical wiring 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 the click has to sound.
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 the filtering element;
3. It is necessary to check the filter and pipelines for availability of ice or wax in the winter, - drive the car into the heated garage, add to system of gasoline;
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 nipple nut of a fuel-supply line of a faulty nozzle turns of the engine will not fall.
10. The fuel pump of high pressure (FPHP) is faulty.
11. Too low pressure of a compression.

The starter functions without engine provorachivaniye

1. The starter gear wheel is jammed.
2. Teeths of a gear wheel of a starter or wreath of a flywheel 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. Passability 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. Compression pressure in cylinders is not enough, TNVD of the diesel engine is faulty, or its adjustment is broken.

Gearing of a starter happens is too noisy or with difficulty

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

The engine is started, but at once becomes deaf

1. The engine immobilizator is faulty.
2. The electrical wiring is faulty, or fastening of wires on plugs of the coil or the generator weakened.
3. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
4. Basic installations of the module of management of the engine (ESM) are broken.
5. Damage to system of release / the catalytic converter has places.
6. Losses of depression through the pro-masonry surfaces of the inlet pipeline or 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. Wiretap the working engine by means of a stethoscope or a piece of a fuel hose. Existence of the hissing sound will allow to reveal a source of "leak" of vacuum. It is possible to use solution of soap water for check not less effectively.
2. Violation of serviceability of functioning of components of a power supply system or electric equipment takes place.
3. Passability of the valve of system of the operated ventilation of a case is broken.
4. Passability of the air filter is broken.
5. The fuel pump does not provide giving of enough fuel to injectors of system of injection.
6. Leaks through laying of a head of cylinders take place, - perform measurement of compression pressure in engine cylinders (see the Head Dvigatel).
7. Working ledges of cams of the camshaft are worn-out.

Diesel models

1. Quality of connections of fuel hoses on TNVD and the fuel filter is broken.
2. Fastening of TNVD is mechanically damaged or weakened.
3. Are mixed by junctions of the returnable pipeline and 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 the filtering element;
3. It is necessary to check the filter and pipelines for availability of ice or wax in the winter, - drive the car into the heated garage, add to system of gasoline;
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 nipple nut of a fuel-supply line of a faulty nozzle turns of the engine will not fall.
7. The fuel pump of high pressure (FPHP) is faulty. Establish new, or obviously serviceable TNVD for check.

Admissions of ignition 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 an electrical wiring is faulty.
4. Low-quality fuel is filled, or passability of the fuel filter is broken.
5. Losses of depression in the inlet pipeline or through hose connections take place.
6. There is not enough, or compression pressure in cylinders is distributed unevenly.
7. Violations in work of a control system of the engine take place.

Admissions of ignition take place during the movement on transfer

1. The fuel filter is blocked or pollution of a power supply system 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 an electrical wiring takes place.
5. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
6. There is not enough or compression pressure is distributed between cylinders unevenly.
7. The system of ignition is faulty.
8. Losses of depression on the throttle case, the inlet pipeline or through vacuum hoses take place.

The engine spontaneously becomes deaf

1. Adjustment of turns of idling is broken.
2. Passability of the fuel filter is broken, or moisture or dirt got to a power supply system.
3. The 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 the Head of the Power supply system and production of the fulfilled gases). Also check a condition of VV of an electrical wiring.
6. Losses of depression 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 cleaner 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 the 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 of that grade is filled. Fill in in a tank fuel with the required octane number.
9. The adjusting valve of a turbocompressor (is damaged at the corresponding complete set).
10. The activator of the camshaft of shift of phases GRM is faulty.
11. Insufficiently compression pressure, or uniformity of its distribution between cylinders is broken.

In addition for the diesel engine

1. The air cleaner is littered.
2. Uneven 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 determined.
4. The fuel filter or TNVD (nozzle) is littered.
5. Adjustment of the maximum frequency of rotation of a bent shaft is broken.

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

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 an electrical wiring) takes place.
3. The system of injection of fuel needs adjustment, or its components are excessively worn-out.
4. Losses of depression 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 an electrical wiring is broken.

At the movement with acceleration or uphill there are detonation sounds

1. Low-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 of that type are established.
4. The basic ECM installations are broken.
5. The detonation sensor is faulty.
6. Depression losses take place.

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

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 of vapors of fuel (EVAP) is broken.
4. 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 excessively smoke-filled

1. Black smoke:
   
   a) The air cleaner 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 determined.
2. Blue smoke:
   
   a) Burning of oil in the combustion chamber owing to wear of piston rings, high level of oil in the air cleaner, wear of epiploons in covers of a turbocompressor, formation of thinnesses in laying between a block case and a turbocompressor, - repair the engine, establish the normal level of oil, replace epiploons, tighten bolts of fastening of a turbocompressor 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 a nozzle because of malfunction of the valve or break of a spray, - grind in the valve or replace a nozzle.
3. White or brown smoke:
   
   a) Low temperature in the cooling system, - check the thermostat;
   b) Bad work of nozzles owing to wear or break of a spray, - 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 the Head Sistemy of electric equipment of the engine).
2. Level of electrolyte is insufficient or the battery is strongly discharged.
3. Corrosion of plugs of the battery takes place or fastening of tips of wires on them weakened.
4. The generator does not provide the required charge current.
5. The electrical wiring of a charging contour is torn off or is in any other manner damaged or fastening of wires on plugs weakened.
6. Short circuit of an electrical wiring creates continuous leakage of the 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 is damaged (only a 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, then damage, as a rule, to 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 the regulator of tension of the generator.
4. Brushes are worn-out.
5. The wire between the generator and the regulator of tension is damaged.
6. The combination of devices is faulty.

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

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 switching off of ignition

1. Diodes are punched.

Starter

If the starter is not turned, at first it is necessary to check that at the plug No. 50 of the traction relay there was necessary tension (at least 10 V). At negative results of check it is necessary to estimate a starter current contour electrical wiring condition.

For check of serviceability of operation of a starter at a full tension of the battery perform the following operations:

a) Not including transfers, include ignition;
b) Peremknite starter plugs 30 and 50 wire with a 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 state.

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

1. The battery is discharged.
2. Peremknite starter plugs 30 and 50: if the starter rotates, check for 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 current owing to violation of quality or oxidation of contact connections.
5. There is no tension on the plug of the 50th traction relay as a result of break of an electrical wiring, or damage of the switch of a starter.

The starter rotates slowly and does not turn a bent shaft

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

The starter grabs 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. Gear wheel drive components 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 switched-off, - switch-off 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 is not enough or tires not of that size are installed.

Diesel engine

1. Contamination of the returnable pipeline. Blow air the returnable pipeline from TNVD to the 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.

Leak of fuel takes 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. You make gas station only before automatic shutdown of the gun.
3. Take place of leak or evaporation from lines of power supply systems and decrease in toxicity of the fulfilled gases.

The engine is not started

1. At inclusion of a starter the electric fuel pump does not work (noise from work is not heard). Slightly knock on a pump housing to release the 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 electrical wiring).
2. The relay of the fuel pump is faulty.
3. Valves of injectors stuck. Check injectors, if necessary replace. Check giving of tension for injectors, - disunite the contact socket of an injector, and connect a diode lamp sampler to a wire and include a starter: the lamp has to begin to blink.
4. There is no signal from the sensor of ignition of Hall or the sensor of temperature of cooling liquid. Check a condition of the corresponding electrical wiring, carry out a survey of memory of system of onboard self-diagnostics.
5. Fuel pipelines are damaged, littered or untight, there are defects of hoses.
6. The fuel filter is littered.
7. To the inlet highway as a result of violation of tightness excess air podsasyvatsya.
8. Vacuum pipelines are damaged or untight
9. Pressure regulator is damaged, - check residual pressure.
10. The sensor of provision of a butterfly valve is damaged.
11. There is no power supply of the block of electronic control by the engine.
12. Availability of ice or wax in the filter or pipelines of the diesel engine.
13. Ventilation of the fuel tank is hammered, the filter in a tank is littered.
14. Preheat does not work.
15. The valve of a cut-off 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 nipple nut of a fuel-supply line of a faulty nozzle turns of the engine will not fall.
18. TNVD is faulty.

The cold engine is started badly, works unstably

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

The warm engine is badly started, works unstably

1. The system of an admission of air is untight. 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 speed for a short time increases, eliminate untight places.
2. The backpressure valve of the fuel pump is damaged.
3. Leaks in fuel system.
4. Elevated pressure of fuel in a power supply system.
5. Malfunction of system of catching of vapors of fuel.
6. The returnable fuel-supply line to a tank is hammered or crumpled.
7. Valves of injectors stuck. Check injectors, if necessary replace. Check giving of tension for injectors, - disunite the contact socket of an injector, and connect a diode lamp sampler to a wire and include a starter: the lamp has to begin to blink.
8. There is no signal from the sensor of ignition of Hall or the sensor of temperature of cooling liquid. Check a condition of the corresponding electrical wiring, carry out a survey of system of onboard self-diagnostics.
9. To the inlet highway as a result of violation of tightness excess air podsasyvatsya.
10. Pressure regulator is damaged, - check residual pressure.
11. The sensor of provision of a butterfly valve is damaged.
12. There is no power supply of the block of electronic control by the engine.

The engine works with interruptions

1. Electric connections to the fuel pump are interrupted from time to time. Check a condition of shtekerny connections and sockets of electric wires of the fuel pump, measuring instrument of a stream of air and the relay of the fuel pump. Check a safety lock and places of contacts for the relay of the fuel pump. Clear contacts, if necessary replace.
2. Poor quality of fuel, formation of steam traffic 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 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 is damaged (there is leak of the fulfilled gases).
10. Malfunction of system of catching of vapors of fuel (EVAP).
11. Fastening of fuel hoses to TNVD and the fuel filter of the diesel engine weakened.
12. At connection the giving and returnable TNVD pipelines are mixed by places.
13. Valves of injectors stuck. Check injectors, if necessary replace. Check giving of tension for injectors, - disunite the contact socket of an injector, and connect a diode lamp sampler to a wire and include a starter: the lamp has to begin to blink.
14. There is no signal from the sensor of ignition of Hall or the sensor of temperature of cooling liquid (ECT). Check an electrical wiring, carry out a survey of memory of ECM on existence of codes of malfunctions.
15. To the inlet highway as a result of violation of tightness excess air podsasyvatsya.
16. Vacuum pipelines are damaged or untight
17. Pressure regulator is damaged, - check residual pressure.
18. The sensor of provision of a butterfly valve is damaged.
19. There is no power supply of the block of electronic control by the engine.

The engine works with interruptions on the transitional modes and in the idling mode

1. The system of an admission of air is untight. Check connections of inlet system. Start the engine and grease with gasoline of the place of contact and connection in the soaking-up highway. If engine turns quickly increase, remove a tightness cause of infringement.
2. Idling adjustment is incorrect. Check the 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 contents WITH. Check contents WITH and idling.
2. Too high pressure in fuel system, - check fuel pressure, if necessary replace pressure regulator.
3. The returnable pipeline between the regulator of pressure and the fuel tank is littered or bent. Clean or replace the pipeline.
4. The engine temperature sensor 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 untight.
2. The fuel cut-off valve does not work at the diesel engine.

Lubrication system

The control lamp does not burn after inclusion of ignition

1. The oil pressure sensor is faulty. Include ignition, disconnect a wire from the sensor and close it on "weight", - if the lamp lights up, replace the sensor.
2. On the sensor tension, contacts of a korrozirovana does not move, - check a condition of the corresponding electrical wiring.
3. The control lamp is faulty.
4. The combination of devices is faulty.

The control lamp does not die away after start of the engine

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

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

1. Oil level fell.
2. Short circuit of an electrical wiring 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 bent shaft are damaged

Too low pressure of oil on small turns

The reducing valve stuck abroach because of pollution.

Too high pressure of oil with a frequency of rotation of the engine of 2000 rpm

The reducing valve does not open because of pollution.

Cooling system

Overheat

1. Level of cooling liquid fell.
2. The belt of the 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 it 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-yellow and red-white wires of the sensor the fan has to earn from half 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 check of a cover under pressure.

Overcooling

1. The thermostat is faulty.
2. Indications of the measuring instrument of temperature are inexact.

External leak of cooling liquid

1. Hoses are damaged or destroyed as a result of material aging or their fastening on unions weakened.
2. Epiploons of the water pump are spoiled, - cooling liquid will exude through a control opening in a pump housing.
3. Leaks from internal channels of a radiator or the side tank(s) take place.
4. Leaks through a drain stopper of the engine or release traffic jams of water galleries take place.

Internal leak of cooling liquid

1. Leaks through laying of a head of cylinders take place, - make check of the cooling system pressure.
2. There are cracks on walls of cylinders or in casting of a head.

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 leak of cooling liquid takes 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 the 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. Passability of the cooling system is broken. Merge cooling liquid, wash out system and fill it with 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 fan electric motor safety lock is faulty.
2. The fan switch is faulty, - check whether tension is put to preresistors, remove and check the fan switch.
3. The electric motor is faulty. Check whether tension at the included ignition and the closed fan switch is put to contacts of the motor 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 the regulator

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

Too low power of heating

1. Level of cooling liquid is insufficient.
2. Handles of management of a heater have the heavy course, is faulty, - check assembly of management, 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, it is damaged the bearing.

Automatic Transmission (AT)

In view of complexity of a design of AT it is desirable to make diagnostics of its malfunctions and repairs of components in a workshop of car service or representative 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, excellent from "Р" (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 situation "P" or "N";
4. Transfers switch hardly or randomly.

2. Make adjustment of draft of gear shifting.

Transmission revolves, switches hardly, publishes extraneous noises or does not provide the movement of the car at installation on one of lobbies or the reverse gear

1. There is a set of the possible reasons of the problems listed in heading, however under competence of the amateur mechanic only one of them - the wrong level of transmission liquid gets.
2. Before driving away the car in a workshop of car service check the level and a condition of transmission liquid. Modify level according to requirements of Specifications or replace liquid together with the filter. If the situation did not improve, ask for the help experts.

Leak of transmission liquid takes place

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

Oil has brown color or smells of 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. The ATF level fell.
2. The control system of the engine is faulty.
3. The sensor switch or its electrical wiring 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 also "R" is started in any situation except "Р"

1. Adjustment of the sensor switch of permission of start is broken.
2. Serviceability of functioning of a control system of the engine is broken.
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 the D or R modes

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

Bridges

Extraneous noises

1. Usual road noise. Adjustment is not given 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 the effort of their tightening weakened.

Vibrations

Check a condition of bearings of wheels, serially poddomkrachivy corresponding from corners of the car and rotating a wheel in manual. Listen at the same time to the sounds proceeding from the bearing. Remove bearings and check their state.

Oil leak

Epiploons of power shafts are damaged.

Brake system

The increased brake pedal course

The working contour of a brake path is damaged, - check system for 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 fluid, 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 takes away aside

1. Pressure in tires does not correspond to demanded.
2. Protectors are unevenly 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 unevenly worn-out.

Spontaneous braking

1. The compensation 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 the movement

1. The compensation 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. The beating of a brake disk is excessively big.

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

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

Uneven 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 the 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 the reason in atmospheric influence (humidity of air). If the scratch appears after the long parking at the increased humidity and then vanishes, it is not necessary to do anything.
2. Blocks of inappropriate type are established.
3. The brake disk rotates not parallel to a support.
4. The mine of a support is polluted.
5. Springs of fastening of blocks are bent.
6. Press springs are stretched.

Brake pedal pulsation

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

The control lamp of ABS lights up during the movement

1. Supply voltage (lower than 10 V) is not enough. Check tension. Check whether the control lamp of the generator after start of the engine dies away. If everything is all right, check maple a generator drive belt.
2. Has malfunction of ABS, - check a state and reliability of fixing of terminal connection of mass of the returnable pump (in the hydromodulator).

Suspension bracket and steering

The car takes away at the movement in one of the parties

1. Tires are pumped unevenly up.
2. Defect of tires takes place.
3. Components of a suspension bracket or steering are excessively worn-out.
4. Carrying out adjustment of angles of installation of forward wheels is required.
5. Forward brake mechanisms are taken.

Breakthroughs, pulling or vibrations take place

1. Balancing of wheels is broken or ovality of disks appeared.
2. Bearings of wheels are worn-out, the effort of their tightening weakened 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 the steering drive are insufficiently greased.
4. Adjustment of angles of installation of forward wheels is broken.
5. The hydraulic booster does not develop the required power.

The excessive side play of steering takes place

1. The effort of tightening of bearings of forward wheels weakened.
2. Components of a suspension bracket or steering 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. Passability of hoses or lines of hydraulic system is broken.
4. Air got to hydraulic system, - pump over system.

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

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

Excessive wear of protectors on an outer edge takes place

1. Tires are pumped incorrectly up.
2. Turns are too sharply made.
3. Adjustment of angles of installation of forward wheels (excessive convergence) is broken.
4. The suspension bracket lever is bent or twisted.

Excessive wear of protectors on an inner edge takes place

1. Tires are pumped incorrectly up.
2. Adjustment of angles of installation of forward wheels is broken (divergence).
3. Components of steering are damaged or their fastening weakened.

Local wear of a protector takes place

1. Balancing of wheels is broken.
2. Disks are damaged or bent.
3. Defect of tires takes place.

Defects of brushes of a screen wiper

Slipping

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 in drops at once

The windshield 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 twisted, 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 unevenly.
3. Pressing force the lever is too small, - slightly grease hinges of levers of a screen wiper and spring or install 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.

Uneven wear of a protector

Static and dynamic disbalance of a wheel, perhaps, owing to an excessive side beating of a disk, too big side play in the bearing hinges.

Uneven wear in the middle of a protector

Static disbalance of a wheel, perhaps, owing to an excessive vertical beating.

Strong wear of certain 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 on side edges of a protector (scaly wear)

1. Adjustment of angles of installation of wheels is broken.
2. Tires are worn-out.
3. Shock-absorbers / the torsion 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. The Bystry movement on turns.

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

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

Unilateral wear of a working surface of a protector

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