Safety systems

Problem Possible causes/consequences and Solutions Solutions
(USA only) (USA only)

(Canada only) (Canada only)

The red brake system warning lamp comes on while the engine is running. A warning tone also sounds.

Risk of accident

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

attention to road and traffic conditions. Do not continue driving under 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.

Consult a qualified specialist workshop immediately. Engage the electric parking brake.

Observe the additional display messages in the multifunction display. Consult a qualified specialist workshop immediately.

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

Problem Possible causes/consequences and Solutions Solutions
yellow ABS warning lamp is lit while the engine is running.

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 and hill start assist 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.
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

yellow ABS warning lamp is lit while the engine is running.

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 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.
at a speed above 12 mph (20 km/h). 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:
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

yellow ABS warning lamp is lit while the engine is running. A warning

The yellow ABS warning lamp is lit while the engine is running. A warning tone also sounds.

Risk of accident

EBD is faulty. Therefore, ABS, BAS, BAS PLUS, ESP®, PRE-SAFE®, PRE-SAFE® Brake, the HOLD function and hill start assist 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 ASSIST22 is deactivated.
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

(Canada only) (USA only)

(Canada only)

The red brake warning lamp, the yellow ESP® and ESP® OFF warning

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. Other systems, e.g. BAS, BAS PLUS, EBD, PRE-SAFE®, PRE-SAFE® Brake, the HOLD function and hill start assist, are also not available due to a malfunction.
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.
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

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

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.
away. 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®.

yellow ESP® OFF warning lamp is lit while the engine is running.

The yellow ESP® OFF warning lamp is lit while the engine is running.

Risk of accident

ESP® is 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.

yellow ESP® and ESP® OFF warning lamps are lit while the engine is

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 and hill start assist are not available 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 ASSIST22 is deactivated.
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

yellow ESP® and ESP® OFF warning lamps are lit while the engine is

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 and hill start assist 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.
at a speed above 12 mph (20 km/h). 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:
display. Observe the additional display messages in the multifunction display.
Drive on carefully.
Visit a qualified specialist workshop.

(Canada only) (USA only)

The red indicator lamp for the electric parking brake flashes and/or (Canada only)

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.
SRS warning lamp is lit while the engine is running.

The red SRS warning lamp is lit while the engine is running.

Risk of accident

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.

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