Keywords
 Introduction
1At a glance
2Safety
3Controls
4Operation
5Practical advice
 Where will I find...?
 Troubleshooting
 Engine
 Tyres and wheels
 Electrical system
 Jump-starting, towing and tow-starting
6Technical data

Troubleshooting

Quick Access

Indicator and warning lamps on the instrument panel
Warning signals
Engine
Clutch
Brake system
Steering
Headlamps and turn signals
Windscreen wipers
Fuel and fuel tank

Indicator and warning lamps on the instrument panel

The indicator and warning lamps are listed according to their allocation in the upper and side indicator lamp panel.

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The yellow ABS warning lamp flashes while the vehicle is in motion.

  Risk of accident

ABS has been deactivated due to a malfunction.

The brake system continues to function normally, but without electronic support. The wheels could therefore lock if you brake hard, for example.
  

Drive on carefully and avoid full brake application. Adapt your driving style to suit the road and traffic conditions.

  

Visit a qualified specialist workshop immediately.

The red brake system warning lamp in the upper indicator lamp panel lights up the first time when you apply the brakes.

  Risk of accident

The brake pads / linings have reached their wear limit.

Braking characteristics may be affected.
  

Have the brake pads / linings replaced as soon as possible at a qualified specialist workshop.

The red brake system warning lamp in the upper indicator lamp panel lights up.
  Risk of accident

The brake fluid level is too low.

The brake system is leaking or the brake pads / linings are worn.

Braking characteristics may be affected.
  

Have the brake pads / linings checked immediately at a qualified specialist workshop.

The red brake pressure warning lamp between the displays for charge pressure lights up.

  Risk of accident

The pressure in one or both of the compressed-air brake circuits is too low. The brake system is leaking or has malfunctioned. The vehicle's braking characteristics are changing and the braking performance is degrading. This jeopardises the operating and road safety of the vehicle.

  

Pull over immediately, paying attention to road and traffic conditions.

  

Consult a qualified specialist workshop.

The red SRS indicator lamp goes off when the key is in position 2 in the ignition lock, or it comes on or flickers while the engine is running.

  Risk of injury

The restraint systems have malfunctioned. The airbags or belt tensioners could be triggered unintentionally, or not at all in the event of an accident.
  

Drive on carefully.
  

Visit a qualified specialist workshop immediately.

The red battery indicator lamp lights up when the engine is running.

  Risk of accident

The battery is not being charged. Possible causes are a defective alternator or a torn poly-V-belt.
  

Pull over immediately, paying attention to road and traffic conditions, and check the poly-V-belt.
  

If it is torn: Do not drive any further! Consult the nearest qualified specialist workshop.
  

If it is undamaged: have the vehicle checked as soon as possible at a qualified specialist workshop.

The red battery indicator lamp lights up when the engine is running.

  Risk of accident

The battery is faulty.
  

Pull over immediately, paying attention to road and traffic conditions.
  

Do not continue driving under any circumstances.
  

Contact a breakdown service, e.g. a Mercedes-Benz Service Centre.

The yellow engine oil level warning lamp flashes after the engine is started or while the vehicle is in motion.

The engine oil level has dropped to its lowest level. If the engine oil level falls any further the indicator lamp will light up.
  

Check the engine oil level and top up at the nearest filling station more.
  

If there is visible oil loss from the engine have the fault rectified immediately at a qualified specialist workshop.

The red engine oil pressure warning lamp lights up while the engine is running.

The engine oil pressure is too low.
  

Check the engine oil level and top up at the nearest filling station more.
  

If there is visible oil loss from the engine have the fault rectified immediately at a qualified specialist workshop.

The yellow flame-start system indicator lamp does not light up when the ignition is switched on. The engine cannot be started.

The flame-start system has malfunctioned.
  

Have the flame-start system checked at a qualified specialist workshop.

The yellow diesel engine electronics warning lamp lights up while the engine is running.

There is a malfunction in the diesel engine electronics.
  

Drive on carefully, do not use too much throttle and keep the engine speed below 2,500 1/min. Adapt your driving style to suit the road and traffic conditions.

  

Visit a qualified specialist workshop immediately.

The diesel engine electronics warning lamp lights up while the engine is running.

If the AdBlue gauge indicates an empty tank, the AdBlue tank reserve is empty.
  

Refill AdBlue immediately more.

The diesel engine electronics warning lamp lights up while the engine is running.

There is a fault in the BlueTec® system or a malfunction relating to emissions in the exhaust gas aftertreatment. This malfunction or fault could lead to damage to the BlueTec® system.
  

Have BlueTec® checked as soon as possible at a qualified specialist workshop.

The yellow air-filter contamination warning lamp lights up while the engine is running.

The service limit for the air filter has been reached. The air filter is dirty.
  

Have the air filter replaced as soon as possible at a qualified specialist workshop.

 

The yellow continuous brake indicator lamp or the yellow retarder indicator lamp comes on.

The continuous brake has malfunctioned.
  

Do not engage the continuous brake.
  

Have the continuous brake checked at a qualified specialist workshop.

The yellow ABS warning lamp for the trailer flashes while the vehicle is in motion.

  Risk of accident

Malfunction in the trailer ABS.

The vehicle’s handling and braking characteristics could change. There is a risk that the trailer may be overbraked.
  

Drive on carefully and avoid full brake application. Adapt your driving style to suit the road and traffic conditions.
  

Visit a qualified specialist workshop immediately.

The red ENR indicator lamp comes on.

The ENR has malfunctioned and can only be monitored to a limited extent.

The chassis may not be in the travel position.
  

Drive on carefully and avoid full brake application. Adapt your driving style to suit the road and traffic conditions.
  

Visit a qualified specialist workshop immediately.

The red ENR indicator lamp is flashing.
  Risk of accident

The ENR has malfunctioned and can no longer be monitored.

The chassis may not be in the travel position.
  

Check the level of the chassis frame and drive on carefully if possible. Adapt your driving style to suit the road and traffic conditions.
  

Visit a qualified specialist workshop immediately.

The yellow ENR indicator lamp is flashing.

The pressure in the auxiliary consumer circuit is too low.
  

Start the engine.
  

Run the engine until sufficient reservoir pressure has built up.

The yellow ENR indicator lamp comes on.

The chassis is not in the travel position.
  

Raise or lower the chassis frame after loading more.
  

If it is not possible to raise or lower the chassis frame, switch the ignition off and on once before operation.

The red dropside indicator lamp comes on while you are driving.
  Risk of accident

The dropside is open.
  

Close the dropside.

The red reservoir pressure indicator lamp for the auxiliary consumers circuit (spring-loaded parking brake) comes on while the vehicle is in motion.
  Risk of accident

The pressure in the auxiliary consumer circuit (spring-loaded parking brake) is too low. The brake system is leaking or has malfunctioned. The spring-loaded parking brake cylinder could close automatically. This could cause the wheels on the rear axle to lock.

There is a risk of skidding.
  

Pull over immediately, paying attention to road and traffic conditions.
  

Have the brake system checked at a qualified specialist workshop.

The red automatic transmission warning lamp lights up while the engine is running.

The automatic transmission is not shifting gear correctly. It is no longer possible to reverse the vehicle.

In extreme cases, the vehicle can no longer be driven.
  

If the vehicle can still be driven, continue your journey carefully.
  

If the vehicle can no longer be driven, pull over immediately, paying attention to road and traffic conditions.
  

Have the fault rectified at a qualified specialist workshop.

The red oil temperature warning lamp lights up while the engine is running.

The oil temperature in the automatic transmission is too high.
  

Pull over immediately, paying attention to road and traffic conditions.
  

Run the engine for 2 to 3 minutes at idling speed, then switch off the engine.
  

Observe the notes in the separate operating instructions for the automatic transmission.
  

If there is visible oil loss from the automatic transmission, have the fault rectified immediately at a qualified specialist workshop.

Warning signals

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

You hear a warning signal.
  Risk of injury

The driver has not fastened his seat belt.
  

Fasten your seat belt more.

You hear a warning signal.

The engine speed is too high. You are driving in the overrevving range.
  

Shift up a gear.
  

Select a higher shift range for vehicles with automatic transmission.
  

Brake the vehicle.

You hear a warning signal.

The coolant temperature is too high.
  

Pull over as soon as it is safe to do so and let the engine cool down.
  

Check the coolant level and top up the coolant as necessary more.
  

Have the cooling system checked at a qualified specialist workshop if the coolant needs topping up more often than usual.
  

Make sure that the air supply to the radiator is not obstructed.
  

If the coolant level is OK, consult a qualified specialist workshop.

You hear a warning signal.

Vehicles without BlueTec®:

The engine oil pressure is too low.
  

Pull over as soon as it is safe to do so.
  

Check the engine oil level and top up the oil at the nearest filling station if necessary more.

The engine could otherwise be damaged.

  

If the engine shows signs of oil loss, have the fault rectified immediately at a qualified specialist workshop.

Engine

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The engine does not start. The starter motor can be heard.

There is air in the fuel system.
  

Turn the key back to position 1 in the ignition lock before the next starting attempt.
  

Restart the engine.
 

Remember that excessively long and frequent attempts to start the engine will drain the battery.

If the engine does not start after several attempts:

  

Consult a qualified specialist workshop.

The engine does not start.

The starter motor can be heard. The reserve fuel warning lamp is on and the fuel gauge shows 0.

The tank has run dry.
  

Refuel the vehicle.
  

Bleed the fuel system more.

The engine does not start.

The starter motor cannot be heard.

The battery isolating switch is switched off.
  

Switch on the power supply more.

The engine does not start.

The starter motor cannot be heard.

The on-board voltage is too low (the battery is too weak or discharged).
  

Jump-start the vehicle more.

If the engine still does not start despite the attempt to jump-start it:

  

Consult a qualified specialist workshop.

The engine does not start.

The starter motor cannot be heard.

The battery is discharged or damaged.
  

Check the battery for damage.
  

Recharge the battery more.

The engine does not start.

The starter motor cannot be heard.

The starter motor is faulty.
  

Have the starter motor checked at a qualified specialist workshop.

The oil pressure gauge does not show any pressure.

The engine oil pressure is too low.
  

Pull over as soon as it is safe to do so.
  

Check the engine oil level and top up at the nearest filling station if necessary more.
 

The engine could otherwise be damaged.
  

If there is visible oil loss from the engine, have the fault rectified immediately at a qualified specialist workshop.

A coolant temperature of over +100 °C is displayed.

The coolant temperature is too high.
  

Pull over as soon as it is safe to do so.
  

Once the engine has cooled down, check the coolant level and top up the coolant if necessary more.
  

If the coolant level is OK, consult a qualified specialist workshop.
  

Make sure that the air supply to the radiator is not obstructed.
  

Have the coolant system checked at a qualified specialist workshop if the coolant needs topping up more often than usual.

Clutch

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The clutch is not engaging/disengaging properly.

There is air in the hydraulic clutch operating system.

The hydraulic system is leaking.
  

Check the fluid level more.
  

Have the hydraulic system checked immediately at a qualified specialist workshop.

Brake system

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The brakes have insufficient or no braking power.
  Risk of accident

There is insufficient brake fluid in the hydraulic system.

The hydraulic system is leaking.
  

Pull over as soon as it is safe to do so.
  

Have the hydraulic system checked at a qualified specialist workshop.

The braking effect is uneven.
  Risk of accident

The condition of the tyres is inadequate.
  

Check the tyre condition more.

The braking effect is uneven.
  Risk of accident

The tyre pressure in the individual tyres is different or insufficient.
  

Check the tyre pressure and correct if necessary more.

The brake circuit reservoir pressure is not reached quickly enough or is not reached at all.
  Risk of accident

The air compressor is not supplying enough air or the compressed-air system is leaking.
  

Have the brake system checked immediately at a qualified specialist workshop.

The parking brake cannot be released.

The reservoir pressure in the auxiliary consumer circuit (spring-loaded parking brake) is too low.
  

Have the brake system checked immediately at a qualified specialist workshop.

Steering

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The vehicle is hard to steer. Driving straight ahead is difficult.
  Risk of accident

There is insufficient fluid in the hydraulic system. There is a leak in the hydraulic system.
  

Have the hydraulic system checked immediately at a qualified specialist workshop.

The vehicle is hard to steer. Driving straight ahead is difficult.
  Risk of accident

The power steering pump is not working. The belt drive is loose or has torn.
  

Have the hydraulic system checked immediately at a qualified specialist workshop.

The vehicle is hard to steer. Driving straight ahead is difficult.
  Risk of accident

The tyre pressure in the individual tyres is different or insufficient.
  

Check the tyre pressure more.

Driving straight ahead is difficult. The direction of travel needs to be corrected continually.
  Risk of accident

The steering play is too great.
  

Check the steering play more.
  

Have the steering checked immediately at a qualified specialist workshop.

Headlamps and turn signals

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The headlamps or turn signals are misted up on the inside.

Air humidity is very high.
  

Drive with the headlamps switched on.
 

The headlamps are demisted after a short distance.

The headlamps or turn signals are misted up on the inside.

The headlamp housing or turn signal housing is not sealed and moisture has been able to enter.
  

Have the headlamps or turn signals checked at a qualified specialist workshop.

Windscreen wipers

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The windscreen wipers are jammed.

Leaves or snow, for example, may be obstructing the windscreen wiper movement. The wiper motor has been deactivated.
  

Stop the vehicle as soon as possible. For safety reasons remove the key from the ignition lock.
  

Remove the cause of the obstruction.
  

Switch on the windscreen wipers again.

The windscreen wipers have stopped working completely.

There is a malfunction in the windscreen wiper drive.
  

Select another wiper speed on the combination switch.
  

Have the windscreen wipers checked at a qualified specialist workshop.

Fuel and fuel tank

Risk of accident and injury

Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to carry out the work required.

Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.

In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. There is a risk of an accident and injury if this work is carried out incorrectly.

Problem

Possible cause/consequence

Suggested solutions

The tank has run completely dry.

There is air in the fuel system.
  

Bleed the fuel system more.

Fuel is leaking from the vehicle.
  Risk of explosion

The fuel line or the fuel tank is defective.

Leaking fuel creates a risk of fire or explosion.
  

Switch off the ignition immediately.
  

Remove the key from the ignition lock.
  

Do not start the engine under any circumstances.
  

Consult a qualified specialist workshop.