ECU MERCEDES-BENZ B-Class 2017 W246 Workshop Manual

Drive system
Display messages
Possible causes/consequences and
0050
0050Solutions 00BD
Check Coolant See Check Coolant See
Operator's Manual Operator's Manual The coolant level is too low.
! Avoid making long journeys with too little coolant in the cooling
system. The drive system will otherwise be damaged.
X If the coolant needs topping up more often than usual, have the
cooling system checked at a qualified specialist workshop. 003D
See Operator's Man‐ See Operator's Man‐
ual ual The 12 V battery is no longer being charged.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 128).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. 003D
Stop Vehicle See Stop Vehicle See
Operator's Manual Operator's Manual The 12 V battery is no longer being charged and the battery charge
level is too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the drive system.
X Secure the vehicle against rolling away (Y page 128).
X Do not drive on.
X Do not tow the vehicle.
X Consult a qualified specialist workshop. High-voltage battery
Display messages
Possible causes/consequences and
0050 0050Solutions 00D9
Battery Reserve Battery Reserve
Level Level The condition of charge of the high-voltage battery has dropped into
the reserve range.
When the remaining range is 0 km, the message appears again. The
power available is then continuously reduced. The reduction in power
is represented in the E-CELL display (Y page 152).
X Charge the high-voltage battery. 00D7
Batterieleistung Batterieleistung
zu
zu
gering, Anhalten,
gering, Anhalten,
sofort laden sofort laden(Battery
capacity too low. Stop
Charge immediately) A warning tone also sounds. The E
‑CELL display (Ypage 152) and the
charge level display (Y page 153) go down to 0. The condition of
charge of the high-voltage battery is so low that operation is no longer
possible. The drive system cannot be restarted.
If you then try to restart the drive system, the Batterieleistung
Batterieleistung zu zu
gering,
gering, Anhalten,
Anhalten, sofort
sofortladen
laden(Battery capacity too low. Stop
Charge immediately) message appears.
X Park the vehicle and charge the high-voltage battery. Display
messages
181On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions Blind Spot Assist
Blind Spot Assist
Currently Unavaila‐ Currently Unavaila‐
ble See Operator's ble See Operator's
Manual Manual Blind Spot Assist is temporarily inoperative.
Possible causes are:
R the radar sensor system is temporarily inoperative, e.g. due to elec-
tromagnetic radiation emitted by nearby TV or radio stations or
other sources of electromagnetic radiation
R the radar sensor system is outside the operating temperature range
The yellow 0063indicator lamps also light up in the exterior mirrors.
When the causes stated above no longer apply, the display message
disappears.
Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 128).
X Start the drive system again. Blind Spot Assist Blind Spot Assist
Inoperative Inoperative Blind Spot Assist is faulty.
The yellow
0063indicator lamps also light up in the exterior mirrors.
X Visit a qualified specialist workshop. Parking Pilot Can‐ Parking Pilot Can‐
celed celed The driver's door is open and the driver's seat belt has not been fas-
tened.
X Repeat the parking process with the seat belt fastened and the
driver's door closed. You have inadvertently touched the multifunction steering wheel while
steering intervention was active.
X While steering intervention is active, make sure that the multifunc-
tion steering wheel is not touched unintentionally. The vehicle has started to skid and ESP
®
has intervened.
X Use Parking Pilot again later (Y page 142).Parking Pilot Inop‐
Parking Pilot Inop‐
erative erative You have just carried out a large number of turning or parking maneu-
vers.
Parking Pilot will become available again after approximately ten
minutes (Y page 142).
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Switch off the drive system and start it again.
If the multifunction display still shows the display message: X Visit a qualified specialist workshop. Parking Assist PARKTRONIC is malfunctioning.
X Visit a qualified specialist workshop. Display
messages
183On-board computer and displays Z

Tires
Display messages
Possible causes/consequences and
0050
0050Solutions Please
Please
Correct
Correct Tire
Tire
Pressure
Pressure The tire pressure is too low in at least one of the tires, or the tire
pressure difference between the wheels is too great.
X Check the tire pressures at the next opportunity (Y page 263).
X If necessary, correct the tire pressure.
X Restart the tire pressure monitor (Y page 265).Check Tires Check Tires The tire pressure in one or more tires has dropped significantly. The
wheel position appears in the multifunction display.
A warning tone also sounds.
G WARNING
Tire pressures that are too low pose the following hazards: R they may burst, especially as the load and vehicle speed increase
R they may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may be
greatly impaired
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away (Y page 128).
X Check the tires and, if necessary, follow the instructions for a flat
tire (Y page 241).
X Check the tire pressure (Y page 263).
X If necessary, correct the tire pressure. Warning Tire Mal‐ Warning Tire Mal‐
function function The tire pressure in one or more tires has dropped suddenly. The wheel
position appears in the multifunction display.
G WARNING
Driving with a flat tire poses a risk of the following hazards: R a flat tire affects the ability to steer or brake the vehicle
R you could lose control of the vehicle
R continued driving with a flat tire will cause excessive heat build-up
and possibly a fire
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away (Y page 128).
X Check the tires and, if necessary, follow the instructions for a flat
tire (Y page 241). Display
messages
185On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions Transmission
Transmission
Not
Notin
in
P Risk of Vehicle
P Risk of Vehicle
Rolling Away Rolling Away The driver's door is open or not fully closed and the transmission is in
position R,Nor D.
A warning tone also sounds.
G WARNING
The vehicle may roll away.
There is a risk of an accident.
X Shift the transmission to position P.
X Secure the vehicle against rolling away (Y page 128).
X Close the driver's door completely. Service
Service
Required
Required Do
Do
Not Shift Gears
Not Shift Gears
Visit Dealer Visit Dealer You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
Dis selected:
X Drive to a qualified specialist workshop without shifting the trans-
mission from position D.
If transmission position R,Nor Pis selected:
X Secure the vehicle against rolling away (Y page 128).
X Notify a qualified specialist workshop or breakdown service.
X Do not tow the vehicle. Only Shift to 'P' Only Shift to 'P'
when when
Vehicle
Vehicle is
isSta‐
Sta‐
tionary
tionary The vehicle is moving.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.0065 The tailgate is open.
X Close the tailgate. 0066 The hood is open.
A warning tone also sounds.
G WARNING
The open hood may block your view when the vehicle is in motion.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 128).
X Close the hood. 0051 At least one door is open. A warning tone also sounds.
X Close all the doors. Display
messages
187On-board computer and displays Z

SmartKey
Display messages
Possible causes/consequences and
0050
0050Solutions 00AF
Key Key
Does
Does Not
NotBelong
Belong
to Vehicle
to Vehicle You have put the wrong SmartKey in the ignition lock.
X Use the correct SmartKey. 00AF
Take Your Key from Take Your Key from
Ignition Ignition The SmartKey is in the ignition lock.
A warning tone sounds
X
Remove the SmartKey. 00AF
Obtain a New Key Obtain a New Key The SmartKey needs to be replaced.
X Visit a qualified specialist workshop. 00AF
Replace Key Battery Replace Key Battery The SmartKey battery is discharged.
X Change the battery (Y page 69).00AF
Don't Forget Your Don't Forget Your
Key Key The display message is shown for a maximum of 60 seconds and is
only a reminder.
You open the driver's door with the drive system switched off. The
SmartKey is not in the ignition lock. A warning tone sounds.
X Take the SmartKey with you when you leave the vehicle. 00AF
Key Not Detected Key Not Detected
(red display message) The SmartKey is not in the vehicle.
A warning tone also sounds.
If the drive system is switched off, you can no longer lock the vehicle
centrally or start the drive system.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 128).
X Locate the SmartKey. There is interference from a strong source of radio waves, and as a
result the SmartKey is not detected while the drive system is running.
A warning tone also sounds.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 128).
X Insert the SmartKey into the ignition lock and drive in SmartKey
mode. Display messages
189On-board computer and displays Z

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00E9
0051
The red seat belt warning lamp lights up after the drive system starts, as soon
as the driver's or the front-passenger door is closed.
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 42).
The warning lamp goes out.
There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow them in a secure
place.
The warning lamp goes out. 00E9
0051
The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or front passenger has not fastened their seat belt. The vehicle is being driven faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph
(25 km/h).
X Fasten your seat belt (Y page 42).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicle is being driven faster
than 15 mph (25 km/h) or has briefly been driven faster than 15 mph (25 km/h). X 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. Warning and indicator lamps in the instrument cluster
191On-board computer and displays Z

Safety systems
Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00C6004D
0051
The yellow brake system warning lamp is lit while the drive system is running.
00C6 (USA only) 004D(Canada only): the yellow RBS/brake system warning lamp
is lit while the drive system is running.
The brake system is malfunctioning.
G WARNING
The braking characteristics may be affected.
There is a risk of an accident.
X Drive on taking extra care.
X Visit a qualified specialist workshop immediately. 00C6004D
0051
00C6 (USA only), 004D(Canada only): the yellow RBS/brake system warning
lamp is lit while the drive system is running.
RBS (Recuperative Brake System) is unavailable due to a malfunction.
G WARNING
The braking performance of the electric motor using recuperative braking may be
either reduced or not effective. If you do not make an additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract
the reduced regenerative braking effect by applying the brake yourself.
The brake system continues to function normally, but without the function listed
above.
The braking effect may be impaired.
X Drive on taking extra care.
X Visit a qualified specialist workshop immediately. 0027004D
0051
0027 (USA only), 004D(Canada only): the red brake system warning lamp is lit
while the drive system is running. A warning tone also sounds.
G WARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident.
X 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.
X Secure the vehicle against rolling away (Y page 128).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. 192
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 0027004D
0051
0027 (USA only), 004D(Canada only): the red brake system warning lamp is lit
while the drive system is running. A warning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of an accident.
X 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.
X Secure the vehicle against rolling away (Y page 128).
X Do not add brake fluid. Adding more will not correct the malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction display. 0025
00E500BB
00C6004D
0051
00C6 (USA only), 004D(Canada only): the yellow ABS, ESP ®
, ESP ®
OFF and
RBS/brake system warning lamps are lit while the drive system is running.
ABS (Anti-lock Braking System) is deactivated due to a malfunction. BAS (Brake
Assist), Active Brake Assist, ESP ®
(Electronic Stability Program), RBS, the HOLD
function and hill start assist are also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative braking may be
either reduced or not effective. If you do not make an additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract
the reduced regenerative braking effect by applying the brake yourself.
The brake system continues to function normally, but without the functions listed
above. The wheels could therefore lock if you brake hard, for example.
The steerability and braking characteristics may be severely affected. The braking distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop immediately.
If the ABS control unit is malfunctioning, other systems may also not be available, e.g. the navigation system. Warning and indicator lamps in the instrument cluster
193On-board computer and displays Z

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 0025
00E500BB
00C6004D
0051
00C6 (USA only), 004D(Canada only): the yellow ABS, ESP ®
, ESP ®
OFF and
RBS/brake system warning lamps are lit while the drive system is running.
ABS is temporarily unavailable. BAS, Active Brake Assist, ESP ®
, EBD (Electronic
Brake-force Distribution), the HOLD function and hill start assist are also deacti-
vated, for example.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative braking may be
either reduced or not effective. If you do not make an additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract
the reduced regenerative braking effect by applying the brake yourself.
The brake system continues to function normally, but without the functions listed
above. The front and rear wheels could therefore lock if you brake hard, for exam- ple.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is a risk of an accident.
X 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: X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. 194
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 0025
00E500BB
00C6004D
0051
00C6 (USA only), 004D(Canada only): the yellow ABS, ESP ®
, ESP ®
OFF and
RBS/brake system warning lamps are lit while the drive system is running.
EBD is malfunctioning. Therefore, ABS, BAS, Active Brake Assist, ESP ®
, RBS, the
HOLD function and hill start assist, for example, are also unavailable.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative braking may be
either reduced or not effective. If you do not make an additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract
the reduced regenerative braking effect by applying the brake yourself.
The brake system continues to function normally, but without the functions listed
above. The front and rear wheels could therefore lock if you brake hard, for exam- ple.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. 0025
00E500BB
0027004D
0051
0027 (USA only), 004D(Canada only): the red brake system warning lamp and
the yellow ABS, ESP ®
and ESP ®
OFF warning lamps are lit while the drive system
is running.
ABS and ESP ®
are malfunctioning. BAS, RBS, Active Brake Assist, EBD, the HOLD
function and hill start assist, for example, are also unavailable.
ATTENTION ASSIST is deactivated.
G WARNING
The braking performance of the electric motor using recuperative braking may be
either reduced or not effective. If you do not make an additional effort to apply the brake yourself, the braking effect may not be sufficient. If necessary, counteract
the reduced regenerative braking effect by applying the brake yourself.
The brake system continues to function normally, but without the functions listed
above. The front and rear wheels could therefore lock if you brake hard, for exam- ple.
The steerability and braking characteristics may be severely affected. The braking
distance in an emergency braking situation can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. Warning and indicator lamps in the instrument cluster
195On-board computer and displays Z