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Troubleshooting

Description diagnostics of electronic control and diagnostic codes are listed in Chapter Systems of an electric motor.

This section provides the most simple scheme of finding the causes of malfunctions and failures occurring in knots and systems of the vehicle. Faults and their possible causes are divided into groups on the basis of a certain relationship to the component or system of a vehicle such as the engine cooling system, and the like, moreover, in the text are links to chapters and sections related to these problems.

Keep in mind that the successful completion of the search to solve this problem is not a black magic accessible only experienced professional engineers, and is determined by a combination of specific knowledge and a patient, systematic approach to the problem. Always move from simple to complex, to bring each check to the logic end and try not to miss the obvious fact - anyone can forget to fill fuel in the fuel tank or to leave for the night included lighting.

Finally, you should always try to make a clear picture of the problem and take appropriate steps to prevent recurrence. If an electrical failure occurred due to violation of the quality of contact, at the same time check the status of all other contacts, and the electrical connectors of the system. If the same fuse repeatedly continues to blow, there is no sense in its further replacement - it is necessary to try to determine the cause of failure. Keep in mind that failure of a minor component can be a sign of malfunction of a critical node or an entire system.

Engine

If the engine does not start, you should try to calmly analyze the situation.

Petrol models

The essential requirements for running any of the petrol engine are up serviceability of giving the cylinders an air-fuel mixture and the adequacy of sparks on the spark plugs.

The first thing to make sure of serviceability of giving of fuel.

To determine whether the spark is produced, it should turn out candles, to insert into tips and separately to make weight. One should not hold the tip of the wire or the hands - use insulated pliers. Ask an assistant to start the engine. If the spark is absent, try to determine the cause of failure.

Diagnostic procedures and electronic control system fault codes are also listed in Chapter Systems of an electric motor (see. Sections Checks control ignition and injection, Troubleshooting - general information and preliminary checks, Check and adjust the ignition timing and specifications).

Diesel models

Among the conditions that guarantee the successful launch of any diesel engine include:

• Sufficient to start the rotation of the crankshaft of the engine;
• Sufficient fuel for auto-ignition temperature of the compressed air into the combustion chambers; those. achieving the target pressure of compression and, when running in cold weather, - correct functioning of the glow plug;
• Injection microfine pulverized fuel in the combustion chamber just at some point.

The first thing to make sure of serviceability of a starter, then check the supply of fuel injectors and glow plug operation. Procedure check the status of the glow plug is provided in Section Checking the glow plugs.

The engine does not turn when you try to run

1. There is a corroded battery terminals or loose mounting on them of tips of wires.
2. Discharged or faulty battery. If the tips of the wires are not oxidized and securely attached to the terminals of the battery, turn the key to "ignition" is ON, then turn on the headlights and / or windscreen wipers, - if they do not function - the battery is low.
3. Transmission inaccurately set to "P".
4. Torn off in the circuit wiring system start-up or the wires are loose at the terminals.
5. Starter pinion gear wedged in the crown of the disc drive.
6. Faulty magnetic switch starter.
7. Faulty starter.
8. Faulty ignition switch.

Engine cranks but does not start

Petrol models

1. Wrong is launched. Proceed as follows:

• Cock a lay brake;
• Turn neutral (Manual) / move the selector lever to position "P" or (AT);
• Not squeezing gas pedal, turn the ignition key to the right. Once the engine starts, immediately release the key. If starting a warm engine can not produce when turning his starter for more than 4 seconds, it slowly squeeze the gas pedal. Do not crank the engine more than 30 seconds at a time, before trying again, wait at least 15 seconds;
• When unstable speeds (for example, engine misfiring) in order to avoid failure of the catalytic converter, try to run the engine for a short time and avoid heavy loads - without delay, drive away the car to the service station of the company Mercedes-Benz;
• In areas where the outdoor air temperature drops often below -20 ?� C, we recommend installing heater coolant - help on this matter can be obtained at any service station Mercedes-Benz.

2. Faulty or disconnected engine immobilizer.
3. Faulty fuse electric fuel pump or electronic fuel injection system.
4. The fuel tank is empty or filled with low-quality fuel.
5. Very dirty air filter. Vacuum leaks occur in the elements of the air supply system failure control fuel injection and ignition.
6. The battery is low (the engine is turned too slowly).
7. Oxidized battery terminal connections or weakened their attachment.
8. Faulty fuel pump or damaged his relay - on hearing check if the pump is activated when the ignition.
9. Damaged or excessively humidified ignition system components.
10. Worn or faulty spark plug or spark plug gap is incorrectly set.
11. Torn off or disconnected electric starting system, or is loose wire on the terminals.
12. Broken or disconnected wiring the ignition coil is loose or any of the terminals of the coil.
13. Faulty fuse ECU faulty any of the sensors: Hall pulse sensor, coolant temperature sensor (ECT) or the intake air (IAT).
14. Insufficient compression pressure.

Diesel models

Make sure that during operation of the system pre-bulbs (indicator lamp on) all onboard electrical consumers (lights, rear window heating, radio, etc.) Have been disabled.

1. Wrong is launched. Proceed as follows:

When the engine is cold and the outdoor temperature is below + 5 ?� C:

• Cock a lay brake, depress the clutch pedal;
• On models with AT push the lever to position "P" or "N". Turn the key to "ignition" position 2 and wait for the shutdown of a control lamp of preheat. As soon as the light goes out, start the engine make, not squeezing the gas pedal;
• If at first there are occasional outbreaks continue to rotate the starter until the engine speed has stabilized (but not more than 30 seconds continuously);
• If you are unable to launch, after half a minute then try again, acting in the above described manner.

When the outdoor temperature is above + 5 ?� C, the need for a glow plug engine missing. This applies also to the already warm engine start in colder weather. Do not squeeze the gas pedal.

2. Faulty engine immobilizer.
3. Faulty fuse electric fuel pump or a system of preheat.
4. The engine is cold: Check the operation of the unit preheat.
5. On the electromagnetic shut-off valve is no tension. Connect a voltmeter or a sampler switch on the LED. Turn on the ignition, the LED should light up, otherwise it is necessary to find an open wiring and eliminate it.
6. Faulty solenoid shut-off valve. Check the attachment of the electromagnetic switch, evaluate the state of the contacts. Turn on and turn off the ignition, - in the switch should be clicked.
7. There is a fault in the fuel supply lines or inside the latter hit the air:

• Pipelines or hoses are mechanically damaged or clogged - clean fuel lines and remove air from the lines and filter;
• Clogged fuel filter - replace the filter element;
• In winter, you should check the filter and pipelines on ice or wax presence - pound car heated garage, add in gasoline;
• Clogged ventilation tank or fuel standpipe strainer - clean.

8. Downed adjustment since the start of the fuel supply.
9. Faulty Injector - when you release the choke nuts faulty fuel injector engine speed will not fall.
10. Faulty fuel injection pump (pump).
11. Insufficient compression pressure.

The starter operates without cranking the engine

1. Conjuring starter pinion.
2. Worn or damaged gear teeth of the starter or flywheel.

Difficult to cold start

1. Discharged or insufficiently charged battery.
2. He has been a violation of serviceability of functioning of the power system components or electrical equipment.
3. There is a deposition of wax in the fuel fine filter.
4. Faulty glow plugs of the diesel engine.

Difficult to start a hot engine

Refer also to Section A hot engine will not start.

1. Broken patency of the air filter.
2. He has been a violation of serviceability of functioning of the power system components or electrical equipment.
3. No fuel is supplied to injectors of the injection.
4. He knocked down a corner of an advancing diesel engine fuel supply.
5. Insufficient compression pressure in the cylinders of the diesel engine fuel injection pump is defective or broken his adjustment.

The engagement of the starter is too noisy or with difficulty

1. Worn or damaged gear teeth of the starter or flywheel.
2. Lost starter bolts or weakened the force of tightening.

Engine starts, but immediately stalls

1. Faulty engine immobilizer.
2. Faulty wiring or wires are loose at the terminals of the coil or generator.
3. He has been a violation of serviceability of functioning components of the system or electrical power.
4. Violated the basic settings of the engine control module (ECM).
5. Damage takes place in the exhaust system / catalytic converter.
6. There have been losses of vacuum on the throttle case, the inlet pipeline or through vacuum hoses.

Violate the stability of the engine at idle

Petrol models

1. We have the loss of vacuum. Make sure the tightness of mounting bolts / nuts, check the fact and quality of fastening on the unions on the inlet pipeline of all vacuum hoses. Listen to the running engine with a stethoscope or a segment of the fuel hose. Have a hissing sound will allow to reveal the source of the "leak" of the vacuum - no less effectively you can use to check for a solution of soapy water.
2. He has been a violation of serviceability of functioning components of the system or electrical power.
3. Broken cross-valve system controlled crankcase ventilation.
4. Broken patency of the air filter.
5. The fuel pump does not supply enough fuel to injectors of the injection.
6. Have the leak through the cylinder head gasket, - a measurement of the compression pressure in the cylinders of the engine (see. Chapter Engine).
7. Worn cam lobe of the camshaft.

Diesel models

1. Disturbed quality of connections of fuel hoses on the fuel pump and the fuel filter.
2. Mechanically damaged or weakened mount pump.
3. Mixed up connection return line and fuel line.
4. There is a fault in the fuel supply line:

• Pipelines or hoses are mechanically damaged or clogged - clean fuel lines;
• Clogged fuel filter. Replace the filter element.
• In winter, you should check the filter and pipelines on ice or wax presence - pound car heated garage, add in gasoline;
• Clogged ventilation tank or fuel standpipe strainer - clean.

5. Downed adjustment of pumping fuel.
6. Faulty Injector - when you release the choke nuts faulty fuel injector engine speed will not fall.
7. Faulty fuel injection pump (pump). Set to test a new or known good pump.

There have been gaps in the cylinders at idle

1. Fouled or defective spark plug or spark plug gap is incorrectly set.
2. There is a system component failure or electrical power.
3. Faulty wiring explosives.
4. Fueled substandard fuel or broken fuel filter permeability.
5. We have the loss of vacuum in the intake manifold or via hose connections.
6. Insufficient or unevenly distributed compression pressure in the cylinders.
7. There have been irregularities in the engine management system.

There have been gaps in the cylinders of the engine when the vehicle is in gear

1. Blocked fuel filter, or there is a contamination of the food.
2. Defective or contaminated spark plug or spark plug gap is incorrectly set.
3. There is a system component failure or electrical power.
4. There is a defect in wiring explosives.
5. Faulty system components reduce emissions.
6. Insufficient or unevenly distributed between the cylinder compression pressure.
7. Faulty ignition system.
8. There have been losses of vacuum on the throttle case, the inlet pipeline or through vacuum hoses.

Engine stalls spontaneously

1. Disturbed adjust the idle speed.
2. Broken permeability of the fuel filter or the power supply system is wet or dirty.
3. There is a component failure / information gauges the power system.
4. Faulty system components reduce emissions.
5. Defective or contaminated spark plug or spark plug gap is incorrectly set (see chap. Current care and maintenance). With appropriate equipment and check the wiring condition of explosive.
6. There have been losses of vacuum on the throttle or through vacuum hoses.

Engine does not develop full power

1. There is a system component failure or electrical power.
2. Clogged air cleaner.
3. Defective spark plug or spark plug gap is incorrectly set.
4. Faulty ignition coil.
5. AT fallen liquid level (see chap. Current care and maintenance).
6. Stalled mission.
7. Blocked fuel filter and / or power system hit the dirt / moisture.
8. It refueled the wrong sort. Fill the fuel tank with the required octane.
9. Damaged control valve turbocharger (with appropriate equipment).
10. Faulty actuator camshaft phase shift timing.
11. Insufficient compression pressure or impaired the uniformity of its distribution among the cylinders.

Additionally, the diesel engine

1. Clogged air cleaner.
2. Uneven fuel supply pump to the cylinders. Adjust the engine is warm.
3. Improperly installed at the start of the fuel supply pump.
4. Clogged fuel filter or pump / nozzle.
5. Broken adjustment of the maximum engine speed.

Claps occur in the intake system or a shot in the exhaust system

1. He has been a violation of serviceability of functioning components of the system or electrical power.
2. There is a defect in the secondary circuit of the ignition system (destruction of insulators of spark plugs or damaged wiring explosives).
3. It needs adjusting the fuel injection system, or excessively worn components.
4. There have been losses of vacuum on the throttle case, the inlet pipeline or through vacuum hoses.
5. Jammed valves.
6. Out of order connect wiring explosives.

At movement with acceleration or uphill there are detonation sounds

1. Fueled low-quality fuel.
2. He has been a violation of serviceability of functioning components of the system or electrical power.
3. Installed spark plugs are not the type.
4. Violated basic settings ECM.
5. Faulty knock sensor.
6. We have the loss of vacuum.

The engine continues to run after turning the key to position 0

1. An excessively high idle.
2. There is a failure of electrical equipment, components, control or shut-off valve of the fuel (diesel models).
3. Broken serviceability of functioning of the valve canister purge fuel vapor recovery system (EVAP).
4. Excessive operating temperature of the engine. Possible causes of the violation may be reducing coolant thermostat failure, blockage or malfunction of the radiator water pump.

Too smoky exhaust of the diesel engine

1. Black smoke:

• Dirty air cleaner - flush and refill with fresh oil or replace the item;
• Applied inappropriate fuel - rinse the tank and fuel switching;
• Improperly installed at the start of feed pump.
• Leakproof valve injectors. Check the operation of the nozzle on the stand, if necessary, disassemble the valve and grind or replace nozzle assembly.

2. Blue Smoke:

• Burning oil in the combustion chamber due to wear of piston rings, the presence of oil in the air cleaner, wear caps seals in the turbocharger, education leaks in the gasket between the crankcase and turbocharger - engine repair, replace the gaskets, tighten the bolts or replace the gasket of the turbocharger;
• No fuel is supplied to one of the nozzles - check the heating exhaust manifold pipes;
• Poor atomization of the fuel injector due to a faulty valve or an open spray - grind valves or replace the nozzle.

3. White or brown smoke:

• The low temperature in the cooling system - Check the thermostat;
• Poor performance of the nozzles due to wear or breakage spray - replace the spray.

Electric Motor

Diagnostic procedures and electronic control system fault codes are listed in Chapter Systems of an electric motor.

Reduced capacity or lack of battery charging

1. Worn or broken drive belt, broken or adjustment of its tension.
2. Insufficient level of the electrolyte or deeply discharged battery.
3. There is a corroded battery terminals or loose mounting on them of tips of wires.
4. The generator does not provide the required charging current.
5. Torn off or otherwise damaged wiring or the charging circuit is loose wire on the terminals.
6. Short-circuiting the wiring poses a constant leakage current generated by the battery to the "masses."
7. There is an internal defect in the batteries.

Charging control lamp does not die away at increase in turns

1. Loose drive belt.
2. A damaged overrunning clutch torque converter (only turbo). Remove the generator and turn the alternator drive shaft to the left, - if the working surface of the pulley is not turning, the damage is usually in the overrunning clutch.
3. Faulty voltage regulator / generator. Disconnect the wire (D +) on the back side of the generator and switch on the ignition. The following is to check the status of the voltage regulator of the generator.
4. Worn brush.
5. Damaged wire between the generator and the voltage regulator.
6. Faulty instrument cluster.

Charging control lamp does not light up when you turn the key in the position

1. It burned or otherwise out of service warning lamp on the instrument panel.
2. Faulty Generator.
3. There is a defect in the printed circuit board, wiring inside the instrument cluster or lamp socket.

Charging control lamp does not go out when you turn the key to position 0

1. Breaking through the diodes.

Starter

Contact wiring harness must be secured and not oxidized!

1. If the starter does not turn, you should first check that the terminal number 50 of the traction relay attended the required voltage (10 V minimum). At negative results of the audit should assess the current state of the electrical circuit of a starter (see. Wiring diagrams).
2. To check the health of a starter operation at full voltage of the battery, follow these steps:

• Not including transmission, turn the key to ;
• Jumper terminals 30 and 50 of a starter cable section not less than 4 ^mm 2.

3. If the starter works flawlessly, the cause of the fault to be found in the wires to the starter. If the starter does not work, it should be checked in the removed state.

Starter does not rotate when you turn the ignition switch to

1. The battery is low.
2. Jumper terminals 30 and 50 starter if starter is rotated, check for an open failed to lock the wire 50, and reassess the starter switch.
3. Continuity of supply, quality, or violated its terminal connections, low battery.
4. The weakening of the current as a result of violation of the quality of the contact or oxidation compounds.
5. There is no voltage at terminal 50 of the traction relay as a result of breakage of wiring or damage to the starter switch.

The starter rotates slowly and turns the crankshaft

1. The battery is low.
2. Flooded summer oil.
3. Inadequate flow of current due to the weakened or oxidised sockets.
4. The carbon brushes are not adjacent to the collector, jammed in the guide, worn, broken, oily or dirty.
5. Insufficient distance between brushes and collector.
6. Collector in the grooves or burned and zamaslilsya.
7. There is no voltage at terminal 50 (at least 8).
8. Broken bearing.
9. Faulty magnetic switch.

Starter "grasp", but provides only ryvkoobraznoe cranking

1. Faulty drive gear.
2. Gear contaminated.
3. Faulty flywheel.

Gear starter is disengaged from the flywheel / drive disc

1. Dirty or damaged components of the drive gear.
2. Faulty magnetic switch.
3. Return spring weakened or torn.

The starter continues to run after the release of the ignition key

1. Magnetic switch jammed - immediately switch off the ignition and replace the traction relay.
2. Not turned off the ignition, - disconnect the battery, replace the lock.

Power system

Excessive fuel consumption

All models

1. Dirty or blocked air filter element.
2. Insufficient tire pressure or tire fitted the wrong size.
3. The engine has a mechanical damage. Check the compression ratio, in case of need make corresponding regenerative repair.
4. Excessively high idle speed and maximum speed.

Petrol models

1. There is a fault power system components, electrical and electronic controls.
2. Leaks in the air intake system.
3. There have been damaged in the exhaust system / catalytic converter.

Diesel engine

1. Clogged fuel return pipe. Purge the air in the direction of the pipeline from the pump to the fuel tank.
2. Leakproof fuel system. Visually check all pipes (supply, return and high pressure), fuel filter and fuel pump. Check the system for leaks.

There have been a fuel leak, and / or there is a smell of gasoline

1. There have been a leak in the fuel supply lines and ventilation lines.
2. Overflowing fuel tank. Refuel only until automatic shut-off gun.
3. There have been leaks / evaporation of the lines of power supply systems and reduce emissions.

The engine does not start

Petrol models

1. When the starter electric fuel pump is not working (is not audible noise from work). Lightly tap the pump housing to release the jammed item. Check the supply voltage to the pump (check the serviceability of the protective fuse and tightened the terminals corresponding to the wiring).
2. Faulty fuel pump relay.
3. Zalipla valve injectors. Check the injectors and replace if necessary. Check the supply voltage to the injectors - Disconnect the injector connector, and connect the wire to the diode lamp-sampler and turn the starter: light should start flashing.
4. There is no signal from the sensor plugs Hall or the coolant temperature sensor. Check the condition of the corresponding electrical wiring, make a survey of the system memory on-board self-diagnostics.
5. Damaged, leaking or clogged fuel lines, there are defects of hoses.
6. Clogged fuel filter.
7. In the intake tract as a result of leakage of excess air is drawn.
8. Damaged vacuum lines, or a violation of the integrity of their landing.
9. Faulty pressure regulator - Check the residual pressure.
10. Damaged throttle position sensor (TPS).
11. No power unit electronic engine management (ECM).
12. The presence of ice or wax in the filter or in the pipes of the diesel engine.
13. A blockage in the fuel tank ventilation filter in the tank is clogged.
14. Preheat is not working.
15. Damaged fuel shut off valve diesel engine.

Diesel models

1. Do not operate glow. Check.
2. Do not open the valve stopping delivery of fuel. Check the shut-off valve, engine control units and anti-theft alarm system.
3. There is a fault in the fuel supply system: Check the fuel supply.

• Pipelines pinched, blocked or leaking, there are defects of hoses;
• Clogged fuel filter;
• In winter: the accumulation of ice or wax in the filter and pipes - to drive the car in a heated garage;
• Tank ventilation clogged or impaired permeability filter tank.

4. There is a displacement of the fuel injection timing.
5. There is damage to the nozzle (s), - alternately unscrewing the union nuts, check the operation of the corresponding cylinder.
6. Faulty fuel pump, - try to establish a new or known good pump.

A cold engine is started badly, works unstably

1. CO content does not meet the regulatory requirements - make the appropriate measurement, check the idle speed.
2. Faulty coolant temperature sensor (ECT) or the intake air (IAT).
3. The fuel pressure does not correspond to the desired value.
4. In the intake tract as a result of leakage of excess air is drawn.

Warm up the engine is started badly, works unstably

1. Leaky air intake system. Check the intake system. To do this, leave the engine running at idle and cover places of seals and connections on the intake tract gasoline. If the number of turns for a short time increase, eliminate leaking place.
2. Faulty fuel pump check valve.
3. Leaks in fuel system.
4. Increased pressure in the fuel supply system.
5. Malfunction of the fuel vapor recovery system.
6. Clogged or crushed fuel return line to the tank.
7. Zalipla valve injectors. Check the injectors and replace if necessary. Check the supply voltage to the injectors - Disconnect the injector connector, and connect the wire to the diode lamp-sampler and turn the starter: light should start flashing.
8. There is no signal from the sensor plugs Hall or the coolant temperature sensor. Check the condition of the corresponding electrical wiring, make a survey on-board self-diagnostic system.
9. In the intake tract as a result of leakage of excess air is drawn.
10. Faulty pressure regulator - Check the residual pressure.
11. Damaged throttle position sensor.
12. No power unit electronic engine management.

The engine works with faults

1. The electrical connection to the fuel pump from time to time interrupted. Check the condition of connections and plug connectors of electric wires of the fuel pump, air flow meter and the fuel pump relay. Check the fuse and place pins on the fuel pump relay. Clean the contacts, if necessary replace.
2. Poor quality fuel vapor lock.
3. Too low amount of fuel supply.
4. Faulty fuel filter.
5. Faulty fuel pump.
6. Faulty injectors.
7. Faulty oxygen sensor, breach in the chain of quality management or no mixture heated oxygen sensor.
8. Defective throttle position sensor.
9. Damaged exhaust manifold or exhaust pipe front desk (there are leaks of exhaust gases).
10. Malfunction of the fuel vapor recovery (EVAP).
11. Is loose fuel hose to the fuel pump and the fuel filter of the diesel engine.
12. When connecting mixed up supply and return pipes of the high pressure pump.
13. Zalipla valve injectors. Check the injectors and replace if necessary. Check the supply voltage to the injectors - Disconnect the injector connector, and connect the wire to the diode lamp-sampler and turn the starter: light should start flashing.
14. There is no signal from the sensor plugs Hall or the coolant temperature sensor (ECT). Check the wiring, make a survey for the presence of ECM memory fault codes.
15. In the intake tract as a result of leakage of excess air is drawn.
16. Damaged or leaking vacuum lines
17. Faulty pressure regulator - Check the residual pressure.
18. Damaged throttle position sensor.
19. No power unit electronic engine management.

The engine works with faults in the transient and idle

1. Leaky air intake system. Check the intake system. Start the engine with gasoline and grease the contact and connection in the intake tract. If the engine speed momentarily increases, eliminate the cause of leakage.
2. Invalid idle adjustment. Check the idle speed control, throttle position sensor, lambda adjustment.
3. Full load sensor is defective or wrongly adjusted. Check the throttle position sensor (TPS).

Hot engine does not start

1. Incorrect adjustment of the maintenance WITH. Check the contents of the SB and idling.
2. Too high fuel system pressure - check the pressure of fuel, if necessary replace a pressure regulator.
3. Clogged or bent return line between the pressure regulator and the fuel tank. Clean or replace the pipeline.
4. Faulty motor temperature sensor.
5. Leakproof power system.
6. Leakproof air intake tract.

The diesel engine is unstable idling and breakaway torque of the car from the scene

1. Is loose fuel hose to the fuel pump and the fuel filter. Replace fuel hoses, fix their collars, tighten the hollow bolt.
2. Reversed supply and return lines at the pump. Check the connection of the fuel lines.

The engine continues to run after turning the key to position 0

1. Leakproof injectors.
2. On the diesel engine is not working fuel shut off valve.

Lubrication system

The indicator lamp does not light up when you turn the key in the position

1. Faulty oil pressure switch. Turn on the ignition, disconnect the sensor wire and close it on "weight" - if the lamp lights, replace the sensor.
2. On the sensor is not energized, contacts corrode, - check the condition of the corresponding wiring.
3. Defective warning lamp.
4. Faulty instrument cluster.

The warning lamp does not go out after starting the engine

1. Oil overheated. Eli warning lamp goes out when the gas supply is not required to do anything.

The warning lamp does not go out after a gas or lights while driving

1. Fell oil level.
2. There is a short circuit wiring the oil level sensor.
3. Faulty sensor.

Too low oil pressure at all speeds

1. Fell oil level.
2. Clogged strainer maslozabornika in the sump.
3. Worn oil pump.
4. Damaged crankshaft bearings.

Too low oil pressure at low engine speeds

1. Pressure relief valve stuck in the open position due to contamination.

Too high oil pressure at engine speeds above 2000 per minute

1. Pressure reducing valve does not open due to contamination.

Cooling system

Overheat

1. Fell coolant level.
2. Worn or damaged drive belt broken water pump or adjustment of its tension.
3. Blocked internal channels of a radiator or contaminated (blocked) grille.
4. Faulty thermostat.
5. Broken or cracked blades of the impeller.
6. Faulty gauge-switch fan: the closure of red-yellow and red-and-white sensor wire fan should earn at half speed.
7. Faulty coolant temperature.
8. Faulty water pump.
9. Do not keep the pressure radiator cap, - make a test pressure cap.

Hypothermia

1. Faulty thermostat.
2. Inaccurate temperature meter.

External coolant leak

1. Damaged or destroyed as a result of the aging of the material, or hoses are loose on their unions.
2. Spoiled seals water pump - Coolant will trickle through the inspection hole in the pump housing.
3. There have been leaks of internal channels of a radiator or the side of the tank (s).
4. There have been leaking through the drain plug of the engine or clutch release cork water galleries.

Internal coolant leaks

Internal coolant leaks are usually detected by checking the state of the motor oil. Inspect the blade of the probe and the inner surface of the cover (covers) of cylinders on presence of traces of water and foaming oil.

1. Have the leak through the cylinder head gasket, - make a check of the cooling system pressure.
2. There are cracks on the cylinder walls or in the casting head.

There is a loss of coolant

1. The system fueled excessive amount of coolant.
2. The coolant boils as a result of overheating of the engine.
3. We have the internal and external coolant leaks.
4. Defective radiator cap, - check the pressure cap.

Broken coolant circulation

1. Do not functioning properly the water pump. The easiest way to ensure the functioning of the pump pinching the upper radiator hose when running the engine at idle. If the hose is released, there is a push liquid inside the pump is functioning properly.
2. Broken patency of the cooling system. Drain the coolant (see chap. Current leaving and service), flush the system and fill it with fresh mixture. If the need arises, remove the heatsink and perform his obratnopotochnuyu washing.
3. Worn or damaged water pump drive belt is broken or adjustment of its tension.
4. Conjuring the thermostat.

Heater

The heater fan does not work

1. Fuse defective fan motor.
2. Defective fan switch - check is applied to a predrezistoram stress, remove and check the fan switch.
3. Faulty electric motor. Check, if applied to the contacts of the motor fan voltage when the ignition switch is closed and the fan - if voltage is applied, replace the motor.

The heater fan does not work on one of the steps

1. Faulty predrezistor.

The heater does not turn off the regulator

1. Faulty switch.
2. Cables adjusting the mixing valve damaged or poorly motile.

Too low heat output

1. Insufficient coolant level.
2. Heater control knobs have a heavy course, is faulty, - check the control assembly, if necessary, replace the specified drive cable.

Noise in the fan heater

1. I hit the dirt, leaves, - remove the fan and clean it, clean the air channel.
2. Broken balancing the impeller, the bearing is damaged.

Automatic transmission (AT)

Diagnostic procedures electronic transmission control system and fault codes are given in Chapter Systems of an electric motor.

Given the complexity of the design AT diagnose its faults and repair the components is preferably carried out in the workshop of car-care center or representative office of Mercedes-Benz.

Common problems associated with the operation of the switching mechanism

1. Among the failures related to the violation of traction control switch include the following:

• Starting the engine is possible with the provisions of transmission other than "P" (Park) and "N" (Neutral);
• Indicator of position of transmission differ from really chosen transfer;
• The car moves at the transmission established in position "P" or "N";
• Gears are shifted with difficulty or arbitrarily.

2. Make adjustment of draft of switching gears.

Transmission revolves, is switched hardly, publishes extraneous noise or does not provide the vehicle when you install one of the forward or reverse gear

1. There are many possible causes of the problems listed in the title, but under the competence of the mechanic-fan gets only one of them - an incorrect transmission fluid level.
2. Before you drive off the car in the car service shop check the level and condition of the transmission fluid. Correct level in accordance with the Specification or change the liquid together with the filter. If the situation is not corrected, seek professional help.

Have the transmission fluid leak

1. Liquid AT has a deep red color. Traces of its leaks should not be confused with signs of motor oil which can be demolished in the transmission housing ram air.
2. To identify and locate the source of the leak first remove the transmission from a boat all traces of dirt and grease. Use appropriate surface cleaner and / or make a steam cleaning. Then, take a short trip by car at low speed (to traces of leaks not communicated running stream far from its source). Stop Poddomkratte car and by visual inspection, set the source of the leak. More often than not, as such, are:

• Sump transmission - tighten the fixing bolts and / or replace a lining of the pallet;
• Tube Bay fluid - Replace the rubber seal at the site of entry of the tube into the crankcase Transmission;
• Transmission fluid lines - couplings tighten or replace the line;
• Ventilation tube - full mission and / or it is exposed to water.

The oil has a brown color and smell of burning

1. Insufficient transmission fluid level.

Not included kickdown mode when pressing the pedal (not downshift)

1. Fell level ATF.
2. Faulty engine management system.
3. Faulty sensor switch or wiring.
4. Disturbed adjustment drive a cable of the selector.

The engine does not start at any position of the selector or zapus-repents in a position other than "P", and

1. Disturbed adjustment gauge-switch of the permission of start.
2. Broken serviceability of functioning of the engine management system.
3. Broken cable adjustment selector.

Transmission revolves, jerks or noise when shifting gears. The car does not move when you switch or

1. Fell level ATF.
2. Faulty sensor or its wiring.
3. Broken serviceability of functioning of the engine management system.

Bridges

Background noise

1. Normal traffic noise - not amenable to adjustment.
2. The noise of tires - check the condition of tread and tire inflation pressure.
3. Worn or damaged wheel bearings or weakened the force of tightening.

Vibrations

1. Check the condition of the wheel bearings, alternately poddomkrachivaya corresponding corner of the vehicle and turning the wheel by hand. Listen thus to sounds coming from the bearing. Remove bearings and check their condition.

Oil leaks

1. Damaged seals differentials.

brake system

Before coming to a final conclusion that there is a problem with the brake system, make sure the tires are in good condition and inflated to the required pressure is not broken alignment of the front wheels and the vehicle is not loaded unevenly.

Increased brake pedal travel

1. Faulty work path braking path, - check the system for leaks.

The brake pedal springs and fails

1. The braking path is air - vent the system.
2. Fell the liquid level in the tank GTZ - make an appropriate adjustment, bleed the system.
3. The formation of vapor bubbles. It manifested mainly in the heavy load on the brakes. Replace brake fluid, bleed the system.

Reducing the effect of braking, pedal fails

1. Leakproof hydraulic path.
2. Damaged sleeves or working in the main brake cylinder.

Bad braking despite the great effort you press the pedal

1. Zamasleny brake linings.
2. Installed improper or hardened Pads.
3. Defective brake booster.
4. Worn brake pads.

When braking the vehicle leads to the side

1. The tire pressure is not correct.
2. Unevenly worn treads.
3. Zamasleny brake linings.
4. On one axis have different brake pads.
5. Excessively worn brake pads.
6. Dirty mine supports.
7. Supports corroded - make replacement.
8. Unevenly worn pads.

Spontaneous braking

1. Clogged compensation hole in the brake master cylinder.
2. Insufficient clearance between the actuating rod and piston GTZ.

Brakes heat up during movement

1. Clogged compensation hole in the brake master cylinder.
2. Insufficient clearance between the actuating rod and piston GTZ.

Brakes shiver

1. Established pads inappropriate type.
2. Brake Disc Fitting corroded.
3. An excessively large run-out of the brake disc.

Brake pads away from the brake disc, the wheel is rotated manually with difficulty

1. Corrosion in cylinders of brake calipers. Repair the caliper may replace.

Uneven wear pads

1. Pads installed the wrong type. Replace the pads, set the original pads Mercedes-Benz.
2. Supports corroded - make replacement.
3. Difficult to stroke.
4. Leakproof path of brake system.

The wedge-shaped brake pad wear

1. The brake disk rotates not in parallel a support.
2. Supports corroded - make replacement.
3. Broken up serviceability of functioning of the piston.

The creaking of brakes

1. Often the reason in atmospheric influence (humidity). If squeaking occurs after a long stay at high humidity and then vanishes, nothing else to do.
2. Pads installed the wrong type.
3. The brake disk rotates not in parallel a support.
4. Contaminated mine support.
5. Bend the spring mounting pad.
6. Stretch compression springs.

Pulsating brake pedal

1. Symptom normal operation of ABS.
2. An excessively large run-out of the brake disc.
3. The brake disk rotates not in parallel a support.

ABS warning lamp lights up while driving

1. Insufficient supply voltage (below 10 V). Check the voltage. Check whether the warning lamp goes out after starting the engine generator. If everything is in order, check the V-belt drive of the generator.
2. Has the fault ABS, - check the condition and reliability of fixing the terminal connections of mass return of the pump (in hydromodulator).

Suspension and steering

The car takes the motion to one side

1. Unevenly inflated tires.
2. There is a tire defect.
3. Excessively worn suspension components, or steering.
4. Requires alignment of the front wheels.
5. Prihvachen front brakes.

There are jerks, twitches or vibration

1. Broken wheel balancing or appeared oval disk.
2. Worn wheel bearings, weakened the force of their tightening or adjustment is broken.
3. Worn or damaged rack-absorbers or other suspension components.

There is too much rocking car / "burying" of his nose to the corners or when braking

1. Stand-defective shock absorbers.
2. Damaged suspension components.

Too tight turns the steering wheel

1. Excessive down the liquid level in the tank system hydrostrengthening steering.
2. Improperly inflated tires.
3. Inadequate lubrication of joints steering gear.
4. Broken alignment of the front wheels.
5. Power does not reach the required power.

There is excessive backlash steering

1. Relent tightening the front wheel bearings.
2. Excessively worn suspension components, or steering.

Hydrostrengthening steering system does not develop due effort

1. Worn or damaged power steering pump drive belt is broken or adjustment of its tension.
2. Excessive fluid level dropped.
3. Broken permeability hoses or hydraulic lines.
4. The hydraulic system is air - vent the system.

There is excessive wear protectors (not in one any area)

1. Improperly inflated tires.
2. Broken wheel balancing.
3. Damaged wheels.
4. Excessively worn suspension components, or steering.

There is excessive tread wear on the outside edge

1. Improperly inflated tires.
2. Too sharp turns are made.
3. Broken adjustment of corners of installation of forward wheels (excessive convergence).
4. Bent or twisted wishbone.

There is excessive tread wear on the inner edge

1. Improperly inflated tires.
2. Broken adjustment of corners of installation of forward wheels (divergence).
3. Damaged steering components or weakening their attachment.

There is a local tire wear

1. Broken wheel balancing.
2. Damaged or bent wheels.
3. There is a tire defect.

Defects wiper

Slippage

1. Dirty rubber working elements.
2. Obtrepanny edge brushes are worn or torn rubber working elements.

In the purification of residual water immediately gather in drops

1. The windshield is dirty varnish polish or oil.

Brush cleans sided - one side is good, the other is not

1. Rubber work item is a one-sided wear.
2. Wiper arm is twisted, the brush is not exactly adjacent to the glass.

Untreated surfaces

1. Compromised the reliability of fixing the working elements within the brush.
2. Brush adjacent to the glass evenly.
3. Too low pressing force of the lever - lightly grease the hinges wiper arms and springs or install a new lever.

Tire Defects

Strong tire wear on both sides of the working surface

1. An underinflated tire.

A strong deterioration of the tire in the middle of the working surface over the entire circumference of the tread

1. Too high tire pressure.

Uneven tread wear

1. Static and dynamic unbalance wheel, possibly due to excessive lateral runout, too much play in the bearing joints.

Uneven wear in the middle of the tread

1. The static imbalance of the wheel, possibly due to excessive vertical run.

The strong depreciation of individual sections in the middle of the working surface of the tread

1. The result of heavy braking.

Sawtooth tread wear, often with outside invisible gap fabric base tires

1. Overloading the vehicle. Check the condition of the inner walls of the tire.

Rubber tabs on the side edges of the tread (flake wear)

1. Broken wheel alignment.
2. Worn tires.
3. Defective shock / torsion springs / rack assembly.

The formation of barbs on the same side of the tread of the front wheels

1. Broken toe adjustment.
2. Worn tires.
3. Frequent movement on wavy surfaces. Fast cornering.

Broken cords. First, visible only from the inside

1. Moving over sharp stones, blows of tires, etc. at high speed.

The one-sided wear on the tread surface

1. Check the toe.
2. Has the fault ABS, - check the condition and reliability of fixing the terminal connections of mass return of the pump (in hydromodulator).