Warning and indicator lamps in the instrument cluster

Mercedes-Benz M-Class / Mercedes-Benz M-Class Owners Manual / On-board computer and displays / Warning and indicator lamps in the instrument cluster

Seat belt

Display messages	Possible causes/consequences and Solutions
After starting the engine, the red seat belt warning lamp lights up for six seconds.	The seat belt warning lamp reminds the driver and front passenger to fasten their seat belts. – Fasten your seat belt.
After starting the engine, the red seat belt warning lamp lights up. In addition, a warning tone sounds for up to six seconds.	Risk of injury The driver's seat belt is not fastened. – Fasten your seat belt. The warning tone ceases.
The red seat belt warning lamp lights up after the engine starts, as soon as the driver's or the front-passenger door is closed.	Risk of injury The driver or front passenger has not fastened their seat belt. – Fasten your seat belt. 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 an intermittent audible warning sounds.	Risk of injury The driver or front passenger has not fastened their seat belt. In addition, you are driving faster than 15 mph (25 km/h) or you have briefly driven faster than 15 mph (25 km/h). – Fasten your seat belt. The warning lamp goes out and the intermittent warning tone ceases.
	Risk of injury There are objects on the front-passenger seat. In addition, you are driving faster than 15 mph (25 km/h) or you have briefly driven faster than 15 mph (25 km/h). – 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.

Safety systems

Display messages

Possible causes/consequences and Solutions

Risk of accident

The brake boosting effect is
malfunctioning and the braking characteristics may be affected.

– Pull over and stop the vehicle safely as soon as possible, paying attention to road and traffic conditions. Do not continue driving under any circumstances.

– Engage the electric parking brake.

– Consult a qualified specialist workshop.

– Observe the additional display messages in the multifunction display.

Risk of accident

There is not enough brake fluid in the
brake fluid reservoir.

– Pull over and stop the vehicle safely as soon as possible, paying attention to road and traffic conditions. Do not continue driving under any circumstances.

– Engage the electric parking brake.

– Consult a qualified specialist workshop immediately.

– Observe the additional display messages in the multifunction display.

Do not add brake fluid. This will not rectify the malfunction.

WARNING
Driving with the brake warning lamp illuminated can result in an accident. Have your brake system checked immediately if the brake warning lamp stays on. Do not add brake fluid before checking the brake system.

Overfilling the brake fluid reservoir can result in spilling brake fluid on hot engine parts and the brake fluid catching fire. You can be seriously burned.

Display messages	Possible causes/consequences and Solutions
The yellow ABS warning lamp is lit while the engine is running.	Risk of accident ABS (Anti-lock Brake System) is deactivated due to a malfunction. BAS (Brake Assist), BAS PLUS, ESP® (Electronic Stability Program), PRE-SAFE®, PRE-SAFE® Brake, the HOLD function, hill start assist and ESP® trailer stabilization are therefore also deactivated, for example. The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example. ATTENTION ASSIST is deactivated. – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop. If the ABS control unit is faulty, there is also a possibility that other systems, such as the navigation system or the automatic transmission, will not be available.
The yellow ABS warning lamp is lit while the engine is running.	Risk of accident ABS is temporarily unavailable. BAS, BAS PLUS, ESP®, EBD (electronic brake force distribution), PRE-SAFE®, PRE-SAFE® Brake, the HOLD function, hill start assist and ESP® trailer stabilization are therefore also deactivated, for example. Self diagnosis is not yet complete or the on-board voltage may be insufficient, for example. The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example. ATTENTION ASSIST is deactivated. – Carefully drive a suitable distance making slight steering movements at a speed above 12 mph (20 km/h). The functions mentioned above are available again when the warning lamp goes out. If the warning lamp is still on: – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop.
The yellow ABS warning lamp is lit while the engine is running. A warning tone also sounds.	Risk of accident EBD is faulty. Therefore, BAS, BAS PLUS, ESP®, PRE-SAFE®, PRESAFE ® Brake, the HOLD function, hill start assist and ESP® trailer stabilization are also unavailable, for example. The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example. ATTENTION ASSIST is deactivated. – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop.
The red brake warning lamp, the yellow ESP® and ESP® OFF warning lamps and the yellow ABS warning lamp are lit while the engine is running.	Risk of accident ABS and ESP® are faulty. Therefore, BAS, BAS PLUS, EBD, PRESAFE ®, PRE-SAFE® Brake, the HOLD function, hill start assist and ESP® trailer stabilization are also unavailable due to a malfunction, for example. The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example. ATTENTION ASSIST is deactivated. – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop.
The yellow ESP® warning lamp flashes while the vehicle is in motion.	Risk of accident ESP® or traction control has intervened because there is a risk of skidding or at least one wheel has started to spin. Cruise control or DISTRONIC PLUS is deactivated. – Only depress the accelerator pedal as far as necessary when pulling away. – Ease off the accelerator pedal while the vehicle is in motion. – Adapt your driving style to suit the road and weather conditions. – Do not deactivate ESP®.
The yellow ESP® OFF warning lamp is lit while the engine is running.	Risk of accident ESP® and ESP® trailer stabilization are deactivated. ESP® will not stabilize the vehicle if it starts to skid or if a wheel starts to spin. – Reactivate ESP®. – Adapt your driving style to suit the road and weather conditions. If ESP® cannot be activated: – Have ESP® checked at a qualified specialist workshop.
The yellow ESP® and ESP® OFF warning lamps are lit while the engine is running.	Risk of accident ESP®, BAS, BAS PLUS, PRE-SAFE®, PRE-SAFE® Brake, the HOLD function, hill start assist and ESP® trailer stabilization are unavailable due to a malfunction. ESP® will not stabilize the vehicle if it starts to skid or if a wheel starts to spin. The brake system continues to function normally, but without the functions listed above. ATTENTION ASSIST is deactivated. – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop.
The yellow ESP® and ESP® OFF warning lamps are lit while the engine is running.	Risk of accident ESP®, BAS, PRE-SAFE®, the HOLD function, hill start assist and ESP® trailer stabilization are temporarily unavailable. BAS PLUS and PRE-SAFE® Brake may also have failed. ESP® will not stabilize the vehicle if it starts to skid or if a wheel starts to spin. Self diagnosis is not yet complete. The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example. ATTENTION ASSIST is deactivated. – Carefully drive a suitable distance making slight steering movements at a speed above 12 mph (20 km/h). The functions mentioned above are available again when the warning lamp goes out. If the warning lamp is still on: – Observe the additional display messages in the multifunction display. – Drive on carefully. – Visit a qualified specialist workshop.
The red indicator lamp for the electric parking brake flashes and/or the yellow warning lamp for the electric parking brake lights up.	The electric parking brake is temporarily malfunctioning or defective. – Observe the additional display messages in the multifunction display.
The red SRS warning lamp is lit while the engine is running.	Risk of injury The restraint systems are malfunctioning. The air bags or ETDs may either be triggered unintentionally or, in the event of an accident, not be triggered at all. – Drive on carefully. – Visit a qualified specialist workshop immediately.

WARNING
In the event a malfunction of the SRS is indicated as outlined above, the SRS may not be operational.

For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center immediately to have the system checked. Otherwise the SRS may not be activated when needed in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and unnecessarily which could also result in injury.

Engine

Display messages	Possible causes/consequences and Solutions
The yellow Check Engine warning lamp lights up while the engine is running.	There may be a malfunction, for example: - in the engine management - in the fuel injection system - in the exhaust system - in the ignition system (for vehicles with a gasoline engine) - in the fuel system 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. In some states, you are required by law to immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. If in doubt, check whether such legal regulations apply in the state/province in which you are currently driving.
	Vehicles with a diesel engine: the fuel tank has been run dry. – Start the engine three to four times after refueling. If the yellow Check Engine warning lamp goes out, emergency running mode is canceled. The vehicle need not be checked.
The yellow reserve fuel warning lamp flashes while the vehicle is in motion. In addition, the yellow Check Engine warning lamp may light up.	The fuel system pressure is too low. The fuel filler cap is not closed correctly or the fuel system is leaking. – Observe the additional display messages in the multifunction display. – Check that the fuel filler cap is correctly closed. – If the fuel filler cap is not correctly closed: close the fuel filler cap. – If the fuel filler cap is closed: visit a qualified specialist workshop.
The yellow reserve fuel warning lamp lights up while the engine is running.	The fuel level has dropped into the reserve range. – Refuel at the nearest gas station.
The red coolant warning lamp lights up while the engine is running and the coolant temperature gauge is at the start of the scale.	The temperature sensor for the coolant temperature gauge is defective. The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high. – Pull over and stop the vehicle safely and switch off the engine, paying attention to road and traffic conditions. Do not continue driving under any circumstances. – Apply the electric parking brake. – Consult a qualified specialist workshop.
The red coolant warning lamp comes on while the engine is running.	The coolant level is too low. If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunctioning. The coolant is too hot and the engine is no longer being cooled sufficiently. – Observe the additional display messages in the multifunction display. – Pull over and stop the vehicle safely and switch off the engine, paying attention to road and traffic conditions. – Allow the engine and coolant to cool. – Check the coolant level and add coolant. Observe the warning notes. – If you need to add coolant more often than usual, have the engine coolant system checked. – Make sure that the air supply to the engine radiator is not blocked, e.g. by snow, slush or ice. – At coolant temperatures under 248 °F (120 °C ), drive to the next qualified specialist workshop. – Avoid subjecting the engine to heavy loads, e.g. driving in mountainous terrain, and stop-and-go traffic.
The red coolant warning lamp comes on while the engine is running. A warning tone also sounds.	The coolant temperature has exceeded 248 °F (120 °C ). The airflow to the engine radiator may be blocked or the coolant level may be too low. The engine is not being cooled sufficiently and may be damaged. – Observe the additional display messages in the multifunction display. – Pull over and stop the vehicle safely and switch off the engine, paying attention to road and traffic conditions. – Allow the engine and coolant to cool. – Check the coolant level and add coolant. Observe the warning notes. – If you need to add coolant more often than usual, have the engine coolant system checked. – Make sure that the air supply to the engine radiator is not blocked, e.g. by snow, slush or ice. – At coolant temperatures under 248 °F (120 °C ), drive to the next qualified specialist workshop. – Avoid subjecting the engine to heavy loads, e.g. driving in mountainous terrain, and stop-and-go traffic.

WARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the engine compartment to catch fire. You could be seriously burned.

Steam from an overheated engine can cause serious burns which can occur just by opening the engine hood. Stay away from the engine if you see or hear steam coming from it.

Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the vehicle and do not stand near the vehicle until the engine has cooled down.

If the coolant temperature exceeds 248 °F(120 °C) do not continue driving. The engine will otherwise be damaged.

Driving systems

Display messages

Possible causes/consequences and Solutions

The red distance warning lamp lights up while the vehicle is in motion. A warning tone also sounds.

Risk of accident

The warning is issued if you approach a
stationary vehicle or a vehicle driving ahead of you at too high a speed.

– Be prepared to brake immediately.

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

More information about DISTRONIC PLUS and PRE-SAFE® Brake.

USA only:

The yellow tire pressure monitor warning lamp (pressure loss/malfunction) is lit.

Canada only:

The yellow tire pressure monitor warning lamp (pressure loss) is lit.

Risk of accident

The tire pressure monitor has detected a
loss of pressure in at least one of the tires.

– Stop the vehicle without making any sudden steering or braking maneuvers. Pay attention to the traffic conditions as you do so.

– Observe the additional display messages in the multifunction display.

– Check the tire pressure. If necessary, correct the tire pressure.

– If necessary, change a wheel.

USA only:

The yellow tire pressure monitor warning lamp (pressure loss/malfunction) flashes for 60 seconds and then remains lit.

The tire pressure monitor is faulty.

– Observe the additional display messages in the multifunction display.

– Visit a qualified specialist workshop.

WARNING
Each tire, including the spare (if provided), should be checked at least every two weeks when cold and inflated to the pressure recommended by the vehicle manufacturer on the Tire and Loading Information placard on the driver's door B-pillar or, if available, the tire pressure label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size indicated on the Tire and Loading Information placard or the tire pressure label, you should determine the proper tire pressure for those tires.

As an added safety feature, your vehicle has been equipped with a tire pressure monitoring system (TPMS) that illuminates a low tire pressure telltale when one or more of your tires are significantly underinflated. Accordingly, when the low tire pressure telltale illuminates, you should stop and check your tires as soon as possible, and inflate them to the proper pressure. Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.

Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has not reached the level to trigger illumination of the TPMS low tire pressure telltale.

USA only:
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the system is not operating properly. The TPMS malfunction indicator is combined with the low tire pressure telltale. When the system detects a malfunction, the telltale will flash for approximately 1 minute and then remain continuously illuminated. This sequence will be repeated every time the vehicle is started as long as the malfunction exists. When the malfunction indicator is illuminated, the system may not be able to detect or signal low tire pressure as intended.

TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning properly. Always check the TPMS malfunction telltale after replacing one or more tires or wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the TPMS to continue to function properly.

Warning and indicator lamps in the instrument cluster

See also:

Categories