Safety systems

Display messages Possible causes/consequences and Solutions Solutions
Risk of accidentABS (Anti-lock Braking System), ESP® Risk of accident

ABS (Anti-lock Braking System), ESP® (Electronic Stability Program), BAS (Brake Assist), PRE-SAFE®, the HOLD function and hill start assist are temporarily unavailable.
BAS PLUS and PRE-SAFE® Brake may also have failed.
In addition, the and, warning lamps light up in and the instrument cluster. warning lamps light up in the instrument cluster.
The self-diagnosis function might not be complete, for example.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example.

movements 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).
If the display message disappears, the functions mentioned above are available again.

If the display message continues to be displayed:
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accident

ABS, ESP®, BAS, PRE-SAFE®, the HOLD function and hill start assist are temporarily unavailable.
BAS PLUS and PRE-SAFE® Brake may also have failed.
In addition, the and, warning lamps light up in and the instrument cluster. warning lamps light up in the instrument cluster.
For example, the on-board voltage may be insufficient.
ATTENTION ASSIST20 is deactivated.
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example.
Drive on carefully.
If the display message disappears, the functions mentioned above are available again.
If the display message continues to be displayed:
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accidentABS, ESP®, BAS, PRE-SAFE®, the Risk of accident

ABS, ESP®, BAS, PRE-SAFE®, the HOLD function and hill start assist are unavailable due to a malfunction.
BAS PLUS and PRE-SAFE® Brake may also have failed.
The (Canada only), (USA only)/ , (Canada only), and, warning lamps in the and instrument cluster also light up. warning lamps in the instrument cluster also light up.
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.
Drive on carefully.
Visit a qualified specialist workshop immediately.
Risk of accidentESP®, BAS, PRE-SAFE®, the HOLD function 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.
In addition, the warning lamps light up in and the instrument cluster. warning lamps light up in the instrument cluster.
The self-diagnosis function might not be complete, for example.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the functions listed above.
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).
If the display message disappears, the functions mentioned above are available again.
If the display message continues to be displayed:
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accident

If the display message is shown and the the same time, the Electronic Traction System is deactivated. warning lamp flashes at the same time, the Electronic Traction System is deactivated.
Otherwise, the brakes on the drive wheels could overheat.
warning lamp goes out. Let the brakes cool down until the display message disappears and the warning lamp goes out.
The Electronic Traction System is activated again.
Risk of accidentESP®, BAS, PRE-SAFE®, the HOLD function Risk of accident

ESP®, BAS, PRE-SAFE®, the HOLD function and hill start assist are unavailable due to a malfunction.
BAS PLUS and PRE-SAFE® Brake may also have failed.
In addition, the warning lamps light up in and the instrument cluster. warning lamps light up in the instrument cluster.
ATTENTION ASSIST is deactivated.
The brake system continues to function normally, but without the functions listed above.
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accidentESP®, BAS, PRE-SAFE®, the HOLD function Risk of accident

ESP®, BAS, PRE-SAFE®, the HOLD function and hill start assist are unavailable due to a malfunction. BAS PLUS and PRE-SAFE® Brake may also have failed. In addition, the warning lamps light up in and the instrument cluster. warning lamps light up in the instrument cluster.
ATTENTION ASSIST is deactivated.
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accidentEBD (electronic brake force distribution), Risk of accident

EBD (electronic brake force distribution), ABS, ESP®, BAS, PRESAFE ®, the HOLD function and hill start assist are unavailable due to a malfunction.
BAS PLUS and PRE-SAFE® Brake may also have failed.
In addition, the and, warning lamps light up in and the instrument cluster and a warning tone sounds. warning lamps light up in the instrument cluster and a warning tone sounds.
ATTENTION ASSIST20 is deactivated.
The brake system continues to function normally, but without the functions listed above. The wheels could therefore lock if you brake hard, for example.
Drive on carefully.
Visit a qualified specialist workshop immediately.
The brake pads/linings have reached their wear limit. The brake pads/linings have reached their wear limit.

Visit a qualified specialist workshop.
The red (USA only)/ The red (Canada only) indicator (USA only)/ lamp flashes and a warning tone sounds. (Canada only) indicator lamp flashes and a warning tone sounds.
You are driving with the electric parking brake applied.
Release the electric parking brake.
or
Pull away carefully.
The red (Canada only) indicator (USA only)/ lamp flashes and a warning tone sounds. (Canada only) indicator lamp flashes and a warning tone sounds.
You are making an emergency stop using the electric parking brake.
After the emergency stop: release the electric parking brake lever.
The red (Canada only) indicator (USA only)/ lamp flashes, the yellow (Canada only) indicator lamp flashes, the yellow (USA only)/ (Canada only) (USA only)/ warning lamp lights up and a warning tone sounds. (Canada only) warning lamp lights up and a warning tone sounds.
The electric parking brake is malfunctioning and the braking effect is restricted.
While the vehicle is in motion:
Release the electric parking brake handle.
While the vehicle is stationary:
Switch off the ignition and turn it back on.
Release the electric parking brake.
If the display message continues to be displayed:
Shift the transmission to P.
vehicle against rolling away. Use the folding wheel chock from the vehicle tool kit to secure the vehicle against rolling away.
Consult a qualified specialist workshop.
The yellow (USA only)/ The yellow (Canada only) warning lamp (USA only)/ lights up. Additionally, the red (Canada only) warning lamp lights up. Additionally, the red (Canada only) indicator (USA only)/ lamp may light up. (Canada only) indicator lamp may light up.
The electric parking brake is malfunctioning.
To release:
Pull the electric parking brake handle.
or
Pull away carefully.
Visit a qualified specialist workshop.
To apply:
Switch off the ignition.
the display message disappears. Pull the electric parking brake lever for at least ten seconds, until the display message disappears.
If the display message continues to be displayed:
Shift the transmission to P.
vehicle against rolling away. Use the folding wheel chock from the vehicle tool kit to secure the vehicle against rolling away.
Consult a qualified specialist workshop.
The red (Canada only) indicator (USA only)/ lamp lights up. (Canada only) indicator lamp lights up.
The power supply for the electric parking brake was interrupted.
Pull the electric parking brake handle.
or
Pull away carefully.
or
disappears. Pull the electric parking brake handle until the display message disappears.
The red (Canada only) indicator (USA only)/ lamp flashes and the yellow (Canada only) indicator lamp flashes and the yellow (USA only)/ (Canada only) (USA only)/ warning lamp lights up. (Canada only) warning lamp lights up.
The electric parking brake is malfunctioning.
Switch off the ignition and turn it back on.
Engage or release the electric parking brake.
or
Pull away carefully.
Visit a qualified specialist workshop.
The yellow (Canada only) warning lamp (USA only)/ lights up. The red (USA (Canada only) warning lamp lights up. The red only)/ (Canada only) (USA only)/ indicator lamp flashes for approximately 10 seconds after the electric (Canada only) indicator lamp flashes for approximately 10 seconds after the electric parking brake has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning, e.g. because of overvoltage or undervoltage.
Pull away carefully.
Visit a qualified specialist workshop.
If there is overvoltage or undervoltage:
the battery or restarting the engine. Remove the cause for the overvoltage or undervoltage, e.g. by charging the battery or restarting the engine.
electric parking brake. Switch the ignition off and on, and then engage or release the electric parking brake.
If this does not release the electric parking brake:
Do not drive on.
Consult a qualified specialist workshop.
The yellow (Canada only) warning lamp (USA only)/ lights up. The red (USA (Canada only) warning lamp lights up. The red only)/ (Canada only) (USA only)/ indicator lamp flashes for approximately 10 seconds after the electric (Canada only) indicator lamp flashes for approximately 10 seconds after the electric parking brake has been applied or released. It then goes out or remains lit.
The electric parking brake has overheated.
parking brake during this time. Allow the vehicle to cool down. Do not engage or release the electric parking brake during this time.
vehicle against rolling away. Use the folding wheel chock from the vehicle tool kit to secure the vehicle against rolling away.
again, then engage or release the electric parking brake. When the vehicle has cooled down: switch the ignition off and on again, then engage or release the electric parking brake.
The yellow (USA only)/ The yellow (Canada only) warning lamp (USA only)/ lights up. The red (USA (Canada only) warning lamp lights up. The red only)/ (Canada only) (USA only)/ indicator lamp flashes for approximately 10 seconds after the electric (Canada only) indicator lamp flashes for approximately 10 seconds after the electric parking brake has been applied or released. It then goes out or remains lit.
The electric parking brake is malfunctioning.
brake. Switch the ignition off and on, and then engage the electric parking brake.
If it is not possible to engage the electric parking brake:
Shift the transmission to P.
vehicle against rolling away. Use the folding wheel chock from the vehicle tool kit to secure the vehicle against rolling away.
Consult a qualified specialist workshop.
The red (USA only)/ The red (Canada only) indicator (USA only)/ lamp lights up. (Canada only) indicator lamp lights up.
You attempted to release the electric parking brake while the ignition was switched off.
lock. SmartKey: turn the SmartKey to position 1 in the ignition lock.
KEYLESS-GO: switch on the ignition.
There is a malfunction in the system. The brake system continues to There is a malfunction in the system. The brake system continues to operate normally.
Drive on carefully.
Visit a qualified specialist workshop.
Risk of accidentThere is not enough brake fluid in the Risk of accident

There is not enough brake fluid in the brake fluid reservoir.
Additionally, the red only)/ (Canada only) (USA only)/ warning lamp lights up in the instrument cluster and a warning tone (Canada only) warning lamp lights up in the instrument cluster and a warning tone sounds.
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.
Engage the electric parking brake.
Consult a qualified specialist workshop.
Do not add brake fluid. This will not rectify the malfunction.

WARNING
Driving with the message Check Brake Fluid Level displayed can result in an accident. Have your brake system checked immediately.
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 Solutions
USA only: one or more of the main functions in the mbrace system are USA only: one or more of the main functions in the mbrace system are malfunctioning.
Canada only: one or more of the main functions of the TELEAID system are malfunctioning.
workshop. USA only: have the mbrace system checked at a qualified specialist workshop.
workshop. Canada only: have the TELEAID system checked at a qualified specialist workshop.
Risk of injuryImportant functions of PRE-SAFE® have Risk of injury

Important functions of PRE-SAFE® have failed. All other occupant safety systems, e.g. air bags, remain available.
Visit a qualified specialist workshop immediately.
Risk of accidentPRE-SAFE® Brake is temporarily inoperative Risk of accident

PRE-SAFE® Brake is temporarily inoperative if:
• the DISTRONIC PLUS cover in the radiator grill is dirty.
• the sensors in the bumpers are dirty.
• its function is impaired due to heavy rain or snow.
• the radar sensor system is temporarily inoperative, e.g. due to electromagnetic radiation emitted by nearby TV or radio stations or other sources of electromagnetic radiation.
• the system is outside the operating temperature range.
• the on-board voltage is too low.
PRE-SAFE® Brake is operational again and the display message disappears if:
• the dirt (e.g. slush) drops away while the vehicle is in motion.
• the system detects that the sensors are fully available again.
• the system is within the operating temperature range.
If the display message continues to be displayed:
Clean the DISTRONIC PLUS cover in the radiator grill.
Clean the bumpers.
Restart the engine.
Wait until the battery is sufficiently charged.
Risk of accidentPRE-SAFE® Brake is defective. BAS PLUS or Risk of accident

PRE-SAFE® Brake is defective. BAS PLUS or the distance warning signal may also have failed.
Visit a qualified specialist workshop.
Risk of injuryThere is a malfunction in the SRS Risk of injury

There is a malfunction in the SRS (Supplemental Restraint System). The up in the instrument cluster. warning lamp also lights up in the instrument cluster.

Visit a qualified specialist workshop.
Risk of injurySRS has malfunctioned at the front on the Risk of injury

SRS has malfunctioned at the front on the left or right. The lamp also lights up in the instrument cluster. warning lamp also lights up in the instrument cluster.
Visit a qualified specialist workshop.
Risk of injurySRS has malfunctioned at the rear on the Risk of injury

SRS has malfunctioned at the rear on the left or right. The lamp also lights up in the instrument cluster. warning lamp also lights up in the instrument cluster.
Visit a qualified specialist workshop.
Risk of injurySRS has malfunctioned at the rear center. Risk of injury

SRS has malfunctioned at the rear center. The lights up in the instrument cluster. warning lamp also lights up in the instrument cluster.
Visit a qualified specialist workshop.
Risk of injuryThere is a malfunction in the left-hand Risk of injury

There is a malfunction in the left-hand and/or right-hand window curtain air bag. The up in the instrument cluster. warning lamp also lights up in the instrument cluster.
Visit a qualified specialist workshop.

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.

Display messages Possible causes/consequences and Solutions Solutions
The front-passenger air bag is enabled during the journey, even The front-passenger air bag is enabled during the journey, even though:
• a child, a small adult or an object weighing less than the system's weight threshold is located on the front-passenger seat.
• the front-passenger seat is unoccupied.
The system may detect objects or forces applying additional weight on the seat.
attention to road and traffic conditions. Pull over and stop the vehicle safely as soon as possible, paying attention to road and traffic conditions.
Engage the parking brake.
Switch off the ignition.
Open the front-passenger door.
frontpassenger seat. Remove the child and the child restraint system from the frontpassenger seat.
suitable rear seat. If necessary, secure the child in a child restraint system on a suitable rear seat.
weight. Make sure that there are no objects on the seat adding to the weight.
The system may otherwise detect the additional weight and interpret the seat occupant's weight as greater than it actually is.
the ignition. Keep the seat unoccupied, close the front-passenger door and switch on the ignition.
Observe the and the multifunction display and check the following: indicator lamp and the multifunction display and check the following:
Seat unoccupied and ignition switched on:
• the light up and remain lit. indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS has deactivated the front-passenger air bag.
• the Front Passenger Airbag Enabled See Oper. Manual or Front Passenger Airbag Disabled See Oper. Manual display messages must not appear in the multifunction display.
Wait for a period of at least 60 seconds until the necessary system checks have been completed and to make sure that the display messages do not appear in the multifunction display.
If the conditions are not fulfilled, the system is not operating correctly.
Visit a qualified specialist workshop immediately.

WARNING
If the remains off even after performing the above corrective indicator lamp remains off even after performing the above corrective steps, do not have any children 12 years old and under and other small individuals use the frontpassenger seat until the system has been repaired.

Display messages Possible causes/consequences and Solutions Solutions
The front-passenger air bag is deactivated during the journey even The front-passenger air bag is deactivated during the journey even though an adult or a person larger than a certain size is occupying the front-passenger seat. If additional forces are applied to the seat, the system may interpret the occupant's weight as lower than it actually is.
attention to road and traffic conditions. Pull over and stop the vehicle safely as soon as possible, paying attention to road and traffic conditions.
Engage the parking brake.
Switch off the ignition.
Have the occupant get out of the vehicle.
the ignition. Keep the seat unoccupied, close the front-passenger door and switch on the ignition.
Observe the and the multifunction display and check the following: indicator lamp and the multifunction display and check the following:
Seat unoccupied and ignition switched on:
Rthe light up and remain lit. indicator lamp must light up and remain lit.
When the indicator lamp is on, OCS has deactivated the front-passenger air bag.
Rthe Front Passenger Airbag Enabled See Oper. Manual or Front Passenger Airbag Disabled See Oper. Manual display messages must not appear in the multifunction display.
Wait for a period of at least 60 seconds until the necessary system checks have been completed and to make sure that the display messages do not appear in the multifunction display.
If these conditions are fulfilled, the front-passenger seat can be occupied again. Whether the indicator lamp remains lit or goes out depends on how OCS classifies the indicator lamp remains lit or goes out depends on how OCS classifies the occupant.
If the conditions are not fulfilled, the system is not operating correctly.
Visit a qualified specialist workshop immediately.

WARNING
If the remains lit with an adult occupant on the front-passenger indicator lamp remains lit with an adult occupant on the front-passenger seat even after performing the above corrective steps, do not have any passenger use the frontpassenger seat until the system has been repaired.

    See also:

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