Keywords
  Introduction
  At a glance
  Safety
  Controls
  Operation
  Practical advice
 Where will I find...?
 Display messages
 Troubleshooting
 Locking/unlocking in an emergency
 Resetting triggered NECK-PRO head restraints
 Operating the roll-over bars manually (Cabriolet)
 Changing the batteries
 Changing the bulbs
 Replacing the wiper blades
 Flat tyre
 Battery
 Jump-starting
 Towing and tow-starting
 Fuses
  Technical data

Troubleshooting

Quick Access

Indicator and warning lamps in switches and buttons
Indicator and warning lamps in the instrument cluster
Warning tones
Accident
Seat belt
Fuel and fuel tank
Engine
Automatic transmission*
Parktronic*
Headlamps and turn signals
Windscreen wipers
Windows
Mirrors
Soft-top
Key
KEYLESS GO*
Trailer towing*
Auxiliary heating*
Parking up the vehicle
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.

Indicator and warning lamps in switches and buttons

Problem

Possible cause/consequence

Suggested solutions

One or all of the indicator lamps in the seat ventilation* button are flashing.

There is insufficient voltage because too many consumers are switched on. The seat ventilation* has switched itself off automatically.
  

Switch off consumers that are not required, e.g. reading lamps, interior lighting, etc.
 

The seat ventilation* will automatically switch back on as soon as there is sufficient voltage again.

One or all of the indicator lamps in the seat heating* button are flashing.

There is insufficient voltage because too many consumers are switched on. The seat heating* has switched itself off automatically.
  

Switch off consumers that are not required, e.g. reading lamps, interior lighting, etc.
 

The seat heating* will automatically switch back on as soon as there is sufficient voltage again.

The indicator lamp in the button on the Thermatic/Thermotronic* control is off and flashes when you press the button. The cooling system cannot be switched on.

The cooling system is losing refrigerant.
  

Visit a qualified specialist workshop.

The indicator lamp in the rear-window heating button is flashing. The rear window heating has switched itself off prematurely or cannot be switched on.

There is insufficient voltage because too many consumers are switched on.
  

Switch off consumers that are not required, e.g. reading lamps, interior lighting, etc.
 

The rear window heating will automatically switch back on as soon as there is sufficient voltage again.

Vehicles with automatic child seat recognition on the front-passenger seat*.

The  PASSENGER AIRBAG OFF warning lamp on the centre console is lit.

A special Mercedes-Benz child seat with automatic child seat recognition has been fitted to the front-passenger seat. The front-passenger airbag has therefore been disabled.

Vehicles with automatic child seat recognition on the front-passenger seat*.

The  PASSENGER AIRBAG OFF warning lamp on the centre console is lit.
  Risk of injury

There is no child seat fitted to the front-passenger seat. The child seat recognition has malfunctioned.

  

Remove electronic equipment from the front-passenger seat, e.g.:

  • notebooks

  • mobile phones

  • cards with transponders, e.g. ski passes or access passes

If the PASSENGER AIRBAG OFF warning lamp is still lit:

  

Visit a qualified specialist workshop.

Indicator and warning lamps in the instrument cluster

Problem

Possible cause/consequence

Suggested solutions

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

  Risk of accident

ABS has been deactivated due to a malfunction. ESP® and BAS are also deactivated.

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

If the ABS control unit is faulty, there is also a possibility of malfunctions in other systems, such as the tyre pressure loss warning system*, Parktronic*, the navigation system* or the automatic transmission*.
  

Drive on carefully.
  

Observe the additional messages in the multifunction display more.
  

Visit a qualified specialist workshop as soon as possible.

The yellow ABS warning lamp lights up while the engine is running.
  Risk of accident

ABS has been deactivated due to undervoltage. It is possible that the battery is not being charged.

ESP® and BAS are also deactivated.

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

Switch off consumers that are not required, e.g. reading lamps, interior lighting, etc.
 

ABS will be available again when the battery voltage increases.

The red distance warning lamp* lights up while you are driving.
  Risk of accident

The distance to the vehicle in front is too short for the speed selected.

  

Increase the distance.

The red distance warning lamp* lights up while you are driving. You will also hear a warning tone.
  Risk of accident

You are approaching a vehicle in front at too great a speed. Or Distronic* has detected a stationary obstacle in your line of travel.
  

Be prepared to brake immediately.
  

Pay careful attention to the traffic situation. You may have to brake or take evasive action.

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

  Risk of accident

ESP® or traction control has intervened because at least one wheel has started to spin.

Distronic* is deactivated.
  

Only depress the accelerator pedal as far as necessary when pulling away.
  

Release the accelerator pedal while you are driving.
  

Adapt your driving style to suit the road and weather conditions.
  

Do not deactivate ESP®.

Exceptions: more.

The yellow ESP® warning lamp is lit while the engine is running.
  Risk of accident

ESP® is deactivated. ESP® will not stabilise the vehicle if it starts to skid or a wheel starts to spin.
  

Reactivate ESP®.

Exceptions: more.
  

Adapt your driving style to suit the road and weather conditions.

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

  Risk of injury

The restraint systems are faulty. The airbags or belt tensioners may either be triggered unintentionally or not at all in the event of an accident.
  

Visit a qualified specialist workshop immediately.

The red brake system warning lamp lights up while you are driving. You will also hear a warning tone.

You are driving with the parking brake on.
  

Release the parking brake.
 

The warning lamp goes out and the warning tone ceases.

The red brake system warning lamp lights up while the engine is running.
  Risk of accident

There is insufficient brake fluid in the fluid reservoir.
  

Do not continue driving under any circumstances.
  

Consult a qualified specialist workshop immediately.
  

Observe the additional messages in the multifunction display more.
  

Under no circumstances should you top up the brake fluid. This will not rectify the fault.

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

The coolant level is too low.

The coolant is too hot and the engine is no longer being cooled sufficiently.
  

Stop the vehicle. Pay attention to the traffic conditions as you do so.
  

Allow the engine and coolant to cool.
  

Check the coolant level more. Observe the warning notes. Top up the coolant if necessary.
  

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

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

If the coolant level is correct, the radiator fan may be faulty.

The coolant is too hot and the engine is no longer being cooled sufficiently.
  

If the coolant temperature is less than 120 † you can continue driving to the nearest qualified specialist workshop.
  

In doing so, avoid heavy loads on the engine (e.g. driving in mountainous terrain) and stop-and-go driving.

The red coolant warning lamp lights up while the engine is running. You will also hear a warning tone.

The coolant level is too low.

The coolant temperature has exceeded 120 †. The engine is not being cooled sufficiently and can be damaged.
  

Stop the vehicle. Pay attention to the traffic conditions as you do so.
  

Allow the engine and coolant to cool.
  

Check the coolant level more. Observe the warning notes. Top up the coolant if necessary.
  

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

The red coolant warning lamp lights up while the engine is running. You will also hear a warning tone.

If the coolant level is correct, the radiator fan may be faulty.

The coolant temperature has exceeded 120 †. The engine is not being cooled sufficiently and can be damaged.
  

Do not continue driving under any circumstances.
  

Consult a qualified specialist workshop.

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

Vehicles with diesel engine: the fuel tank has run dry.
  

Start the engine three to four times after refuelling.
 

Emergency running mode is cancelled. The vehicle need not be checked.

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

  • in the engine control system or

  • in the fuel injection system or

  • in the exhaust system or

  • in the ignition system (on vehicles with a petrol engine)

The emission limit values may be exceeded and the engine may be running in emergency mode.
  

Have the vehicle checked as soon as possible at a qualified specialist workshop.

The yellow roll-over bar warning lamp lights up or flashes while the engine is running.

  Risk of injury

The roll-over bars are not ready for operation.
  

Release the roll-over bars manually more.
  

Visit a qualified specialist workshop.

The red seat belt warning lamp lights up for 6 seconds after the motor starts up.

(Only for certain countries)

The seat belt warning lamp reminds you and the front passenger to fasten their seat belt.
  

Fasten your seat belt more.

You will hear a warning tone for a maximum of 6 seconds after the motor starts.

  Risk of injury

The driver's seat belt is not fastened.
  

Fasten your seat belt more.
 

The warning tone ceases.

The red seat belt warning lamp comes on after starting the engine, as soon as the driver's door or the front-passenger door is closed.
  Risk of injury

Either the driver's or the front-passenger seat belt is not buckled.
  

Fasten your seat belt more.
 

The warning lamp goes out.
  Risk of injury

There are objects on the front-passenger seat.
  

Remove the objects from the front-passenger seat and stow them in a secure place.
 

The warning lamp goes out.

The red seat belt warning lamp flashes and you hear an intermittent warning tone.
  Risk of injury

Either the driver's or the front passenger's seat belt is not buckled and you are driving faster than 25 km/h or have driven faster than 25 km/h for a short time.
  

Fasten your seat belt more.
 

The warning lamp goes out and the intermittent warning tone ceases.
  Risk of injury

There are objects on the front-passenger seat and you are driving faster than 25 km/h or have driven faster than 25 km/h for a short time.
  

Remove the objects from the front-passenger seat and stow them in a secure place.
 

The warning lamp goes out and the intermittent warning tone ceases.

The yellow reserve fuel warning lamp lights up while the engine is running.

The level of fuel has fallen below the reserve range. Safe operation of the auxiliary heating* can no longer be guaranteed.
  

Refuel at the nearest filling station.

Warning tones

Problem

Possible cause/consequence

Suggested solutions

The anti-theft alarm system* is suddenly triggered.

You opened the vehicle using the emergency key element without first deactivating the anti-theft alarm system*.
  

Switch off the alarm more.

You hear a warning tone.

A message appears in the multi-function display.
  

See the explanations for the display message more.

You hear a warning tone.

You are driving with the parking brake on.
  

Release the parking brake.

You hear a warning tone.

You have opened the driver's door and forgotten to switch off the lights.
  

Turn the light switch to or .

You hear a warning tone.
  Risk of injury

The driver or front passenger has not fastened their seat belt.
  

Fasten your seat belt more.

Accident

Problem

Possible cause/consequence

Suggested solutions

Fuel is leaking from the vehicle.

The fuel line or the fuel tank has been damaged.
  

Immediately turn the key to position 0 in the ignition lock and remove it.
  

Do not restart the engine under any circumstances.

The leaking fuel creates a risk of fire or explosion.

  

Consult a qualified specialist workshop.

You are unable to determine the extent of the damage.

  

Consult a qualified specialist workshop.

You cannot detect any damage.

  

Start the engine as normal.

The NECK-PRO head restraints on the driver's and front-passenger seats have been deployed.

Your vehicle has had a rear collision.
  

Reset the NECK-PRO head restraints more.

Seat belt

Problem

Possible cause/consequence

Suggested solutions

The seat-belt extender is unable to be retracted.
  Risk of injury

The seat-belt extender is defective.
  

Push back the seat-belt extender with force.
  

Have the seat-belt extender checked at a qualified specialist workshop.

If the seat-belt extender is unable to be pushed back:

  

Do not drive on.
  

Consult a qualified specialist workshop.

Fuel and fuel tank

Problem

Possible cause/consequence

Suggested solutions

Fuel is leaking from the vehicle.

The fuel line or the fuel tank is defective.

  

Turn the key to position 0 in the ignition lock immediately and remove it.
  

Do not restart the engine under any circumstances.

The leaking fuel creates a risk of fire or explosion.

  

Consult a qualified specialist workshop.

The fuel filler flap cannot be opened.

The fuel filler flap is not released.
  

Unlock the vehicle more.

The opening mechanism is jammed.
  

Consult a qualified specialist workshop.

The fuel tank has been run completely dry on a vehicle with a diesel engine.

There is air in the fuel system.
  

Refuel the vehicle.
  

Switch on the ignition for approximately 10 seconds (key in position 2 in the ignition lock)
  

Start the engine continuously for up to 40 seconds until it runs smoothly.
 

The fuel system is now free of air.

If the engine does not start:

  

Wait two minutes.
  

Repeat the starting procedure for up to 40 seconds.

If the engine still does not start:

  

Consult a qualified specialist workshop.

Engine

Problem

Possible cause/consequence

Suggested solutions

The engine will not start. You can hear the starter motor operating.

  • There may be a malfunction in the engine electronics.

  • There may be a malfunction in the fuel supply.
  

Turn the key back to position 0 in the ignition lock before the next starting attempt.
  

Try to start the engine again more. When doing so, 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.

Vehicles with a diesel engine:

The engine will not start. You can hear the starter motor operating. The reserve fuel warning lamp is on and the fuel gauge shows 0.

The fuel tank has been run dry.
  

Refuel the vehicle.
  

Bleed the fuel system more.

The engine will not start. You cannot hear the starter motor operating.

The on-board voltage is too low because the starter battery is too weak or discharged.
  

Jump-start the vehicle more.

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

  

Consult a qualified specialist workshop.

Vehicles with a petrol engine:

The engine is not running smoothly and is misfiring.

The engine electronics or a mechanical component of the engine control unit have been damaged.
  

Only depress the accelerator pedal slightly.
  

Have the cause rectified immediately at a qualified specialist workshop.
 

Otherwise, non-combusted fuel may get into the catalytic converter and damage it.

A coolant temperature of over 120 °C is displayed. The coolant warning lamp may also be on and a warning signal may sound more.

The coolant level is too low. The coolant is too hot and the engine is no longer being cooled sufficiently.
  

Stop as soon as possible and allow the engine and the coolant to cool down.
  

Check the coolant level more. Observe the warning notes as you do so and top up the coolant if necessary.

If the coolant level is correct, the radiator fan may be faulty. The coolant is too hot and the engine is no longer being cooled sufficiently.
  

If the coolant temperature is less than 120°C, you can continue driving to the nearest qualified specialist workshop.
  

Avoid heavy loads on the engine as you do so, e.g. when driving on mountain roads and stop/start driving.

Automatic transmission*

Problem

Possible cause/consequence

Suggested solutions

Problems with gearshifts.

The transmission is losing oil.
  

Have the transmission checked at a qualified specialist workshop immediately.

The acceleration ability is deteriorating.

The transmission no longer changes gear.

The transmission is in emergency mode.

It is only possible to shift into 2nd gear and reverse gear.
  

Stop the vehicle.
  

Move the selector lever to P.
  

Turn the key to position 0 in the ignition lock.
  

Wait at least 10 seconds before restarting the engine.
  

Move the selector lever to position D or R.
 

If D is selected, the transmission shifts into 2nd gear; if R is selected, the transmission shifts into reverse gear.
  

Have the transmission checked at a qualified specialist workshop immediately.

Parktronic*

Problem

Possible cause/consequence

Suggested solutions

Only the red segments in the Parktronic warning displays are lit. You also hear a warning signal for approximately two seconds.

Parktronic is deactivated after approximately 30 seconds and the indicator lamp in the Parktronic button lights up.

Parktronic has malfunctioned and has switched itself off.
  

If problems persist, have Parktronic checked at a qualified specialist workshop.

Only the red segments in the Parktronic warning displays are lit. Parktronic is deactivated after approximately 20 seconds.

The Parktronic sensors are dirty or there is interference.
  

Clean the Parktronic sensors more.
  

Switch the ignition back on.

Only the red segments in the Parktronic warning displays are lit. Parktronic is deactivated after approximately 20 seconds.

The problem may be caused by an external source of radio or ultrasound waves.
  

See if Parktronic functions in a different location.

Headlamps and turn signals

Problem

Possible cause/consequence

Suggested solutions

The headlamps or the turn signals in the exterior mirrors 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 headlamp housing is not sealed and moisture has been able to enter.
  

Have the headlamps checked at a qualified specialist workshop.

Windscreen wipers

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.
  

For safety reasons, you should remove the key from the ignition lock.
  

Remove the cause of the obstruction.
  

Switch the windscreen wipers back on.

The windscreen wipers fail completely.

The windscreen wiper drive is malfunctioning.
  

Select another wiper speed on the combination switch.
  

Have the windscreen wipers checked at a qualified specialist workshop.

Windows

Problem

Possible cause/consequence

Suggested solutions

A side window blocks while closing.
  Risk of injury

A side window blocks during automatic or manual closing, and the closing procedure is interrupted.

An object is blocking the side window and preventing it from closing.
  

Release the switch.
 

The side window opens slightly.
  

Open the side window.
  

Remove the object(s).
  

Close the side window.
  

Make sure that nobody becomes trapped.

A side window blocks while closing.
  Risk of injury

You cannot see the cause.

  

Pull and hold the window switch until the side window is closed.
  

Make sure that nobody becomes trapped.

The side window in the driver's door does not close fully when you pull the switch beyond the pressure point and then release it.
  Risk of injury

You cannot see the cause.

The side window in the driver's door stops during automatic closing, the closing procedure is interrupted and the window opens again slightly.
  

Pull and hold the switch until the side window in the driver's door is closed.

If the side window in the driver's door has opened again slightly:

  

Pull the switch beyond the pressure point again within five seconds and then release it.
 

The side window in the driver's door is closed without the anti-entrapment function.
  

Make sure that nobody becomes trapped.

The anti-entrapment function is switched back on again automatically after approximately five seconds.

Mirrors

Problem

Possible cause/consequence

Suggested solutions

An exterior mirror has been pushed forwards or backwards out of position.

Vehicles without exterior mirrors that can be folded in/out electrically:

  

Push the mirror into the correct position manually.

Vehicles with exterior mirrors that can be folded in/out electrically*:

  

Press the mirror-folding button* more repeatedly in quick succession until you hear a distinct click.
 

The mirror housing is engaged again and you can adjust the mirror as usual more.

Soft-top

Problem

Possible cause/consequence

Suggested solutions

The soft-top will not open or close.

The ignition is not switched on.
  

Make sure that the key is in position 2 in the ignition lock.

The parking brake is not depressed.
  

Depress the parking brake more.

The boot lid is open.
  

Close the boot lid more.

The boot separator is not closed.
  

Close the boot separator more.

The skibag cover is open.
  

Close the skibag cover more.

The roll-over bars have been deployed.
  

Visit a qualified specialist workshop.

The soft-top mechanism or control system is defective.
  

Close the soft-top with the emergency mechanism if necessary more.
  

Visit a qualified specialist workshop.

The soft-top was opened and closed several times in succession. The soft-top drive has been deactivated automatically for safety reasons.

You can open or close the soft-top again after approximately ten minutes.

  

Switch the ignition off and then on again.
  

Repeat the opening or closing procedure.

Key

Problem

Possible cause/consequence

Suggested solutions

You cannot lock or unlock the vehicle using the key.

The key batteries are discharged or nearly discharged.
  

Point the tip of the key at the driver's door handle from close range and try to open the vehicle again.

If this does not work:

  

Lock or unlock the vehicle using the emergency key element more.
  

Check the key batteries more and change them if necessary more.

The key is faulty.
  

Lock or unlock the vehicle using the emergency key element more.
  

Have the key checked at a qualified specialist workshop.

The battery charge indicator lamp of the key does not go on during the test.

The key batteries are discharged.
  

Change the batteries more.

You have lost a key.

  

Have the key cancelled at a Mercedes-Benz Service Centre.
  

Report the loss immediately to the vehicle insurers.
  

If necessary, have the manual locks changed too.

You have lost the emergency key element.

  

Report the loss immediately to the vehicle insurers.
  

If necessary, have the manual locks changed too.

The key cannot be turned in the ignition lock.

The key has been in position 0 for a considerable time.
  

Remove the key and reinsert it into the ignition lock.
  

Check the vehicle battery and recharge it if necessary more.
  

Start the engine.

The on-board voltage is too low.
  

Switch off non-essential consumers, e.g. seat heating* or interior lighting, and try to turn the key again.

If this does not work:

  

Check the vehicle battery and recharge it if necessary more.
or
  

Jump-start the vehicle more.
or
  

Consult a qualified specialist workshop.

KEYLESS GO*

Problem

Possible cause/consequence

Suggested solutions

You cannot lock or unlock the vehicle using the KEYLESS GO key.

The KEYLESS GO key batteries are discharged or nearly discharged.
  

Lock or unlock the vehicle using the remote control function of the KEYLESS GO key. To do this, point the tip of the key at the driver's door handle from close range and try to open the vehicle again.

If this does not work:

  

Lock or unlock the vehicle using the emergency key element more.
  

Check the KEYLESS GO key batteries more and change them if necessary more.

There is a fault with KEYLESS GO.
  

Check the KEYLESS GO key batteries more and change them if necessary more.
  

Have the KEYLESS GO key checked at a qualified specialist workshop.

There is interference from a powerful source of radio waves.
  

Lock or unlock the vehicle using the emergency key element more.

The battery check lamp in the KEYLESS GO key does not light up when tested.

The KEYLESS GO key batteries are discharged.
  

Change the batteries more.

The vehicle cannot be started using the KEYLESS GO key and the KEYLESS GO button. The KEYLESS GO key is in the vehicle.

A door is open. The key therefore cannot be detected so easily.
  

Close the door and try to start the vehicle again.

You did not depress the brake when starting the engine.
  

Depress the brake pedal and press the KEYLESS GO button.

There is interference from a powerful source of radio waves.
  

Start your vehicle using the KEYLESS GO key in the ignition lock.

You have lost the KEYLESS GO key.

  

Have the KEYLESS GO key cancelled at a Mercedes-Benz Service Centre.
  

Report the loss immediately to the vehicle insurers.
  

If necessary, have the manual locks changed too.

Trailer towing*

Problem

Possible cause/consequence

Suggested solutions

The ball coupling cannot be locked.

The key cannot be removed from the ball coupling.
  Risk of accident

The ball coupling is dirty.

The trailer tow hitch is damaged.
  

Remove the ball coupling and clean it more. If the ball coupling still cannot be locked, remove the ball coupling. It must no longer be used to tow a trailer, as safe operation is not guaranteed.
  

Have the entire trailer tow hitch checked at a qualified specialist workshop.

Auxiliary heating*

Problem

Possible cause/consequence

Suggested solutions

The auxiliary heating does not work.

The fuel tank is only a quarter full.
  

Refuel at the nearest filling station.
  

Have the auxiliary heating checked at a qualified specialist workshop.

The indicator lamp in the auxiliary heating remote control lights up in orange.

The remote control batteries are almost discharged.
  

Replace the remote control batteries more.

The indicator lamp in the auxiliary heating remote control flashes orange.

The remote control batteries are discharged.
  

Replace the remote control batteries more.

The auxiliary heating cannot be switched on using the remote control.

The indicator lamp in the auxiliary heating remote control flashes green.

The signal transmission between the remote control and the vehicle is faulty.