change key battery MERCEDES-BENZ M-Class 2015 W166 Owner's Manual

the battery check lamp flashes twice
(Y page 83).
i If the setting of the locking system is
changed within the signal range of the vehi- cle, pressing the 0037or0036 button:
R locks or
R unlocks the vehicle
The SmartKey now functions as follows:
X To unlock the driver's door: press the
0036 button once.
X To unlock centrally: press the0036but-
ton twice.
X To lock centrally: press the0037button.
The KEYLESS-GO function is changed as fol-
lows:
X To unlock the driver's door: touch the
inner surface of the door handle on the
driver's door.
X To unlock centrally: touch the inner sur-
face of the door handle on the front-
passenger door or the rear door.
X To lock centrally: touch the outer sensor
surface on one of the door handles
(Y page 81).
X To restore the factory settings: press
and hold down the 0036and0037 buttons
simultaneously for approximately six sec-
onds until the battery check lamp flashes
twice (Y page 83). Mechanical key
General notes If the vehicle can no longer be locked or
unlocked with the SmartKey, use the
mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered (Y page 77).There are several ways to turn off the alarm:
X To deactivate the alarm with the Smart-
Key: press the 0036or0037 button on the
SmartKey.
or
X Insert the SmartKey into the ignition lock.
or
X To deactivate the alarm with KEYLESS-
GO: press the Start/Stop button in the igni-
tion lock. The SmartKey must be in the
vehicle.
or
X Lock or unlock the vehicle using KEYLESS-
GO. The SmartKey must be outside the
vehicle.
If you unlock the vehicle using the mechanical key, the fuel filler flap will not be unlocked
automatically.
X To unlock the fuel filler flap: insert the
SmartKey into the ignition lock.
Removing the mechanical key X
Push release catch 0043in the direction of
the arrow and at the same time remove
mechanical key 0044from the SmartKey.
For further information about: R unlocking the driver's door (Y page 88)
R unlocking the cargo compartment
(Y page 93)
R locking the vehicle (Y page 88)82
SmartKeyOpening and closing

Inserting the mechanical key
X
Push mechanical key 0044completely into
the SmartKey until it engages and release
catch 0043is back in its basic position. SmartKey battery
Important safety notes G
WARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention immediately.
Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist workshop.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National
guidelines must be observed during disposal.
In California, see www.dtsc.ca.gov/Hazard-
ousWaste/Perchlorate/index.cfm.
Checking the battery X
Press the 0037or0036 button.
The battery is working properly if battery
check lamp 0043lights up briefly. The battery is discharged if battery check
lamp
0043does not light up briefly.
X Change the battery (Y page 83).
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the 0037or0036 button:
R locks or
R unlocks the vehicle
i You can get a battery at any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the mechanical key out of the Smart-
Key (Y page 82). X
Press mechanical key 0044into the opening
in the SmartKey in the direction of the
arrow until battery compartment cover 0043
opens. Do not hold battery compartment
cover 0043closed while doing so.
X Remove battery compartment cover 0043. SmartKey
83Opening and closing Z

Problems with the SmartKey
Problem
Possible causes/consequences and
0050
0050Solutions You cannot lock or
unlock the vehicle
using the SmartKey. The SmartKey battery is discharged or nearly discharged.
X Try again to lock/unlock the vehicle using the remote control
function of the SmartKey. Point the tip of the SmartKey at the
driver's door handle from close range and press the 0036or
0037 button.
If this does not work:
X Check the SmartKey battery (Y page 83) and replace it if nec-
essary (Y page 83).
X Lock (Y page 88) or unlock (Y page 88) the vehicle using the
mechanical key. The SmartKey is faulty.
X Lock (Y page 88) or unlock (Y page 88) the vehicle using the
mechanical key.
X Have the SmartKey checked at a qualified specialist workshop. You can no longer lock
or unlock the vehicle
using KEYLESS-GO. There is interference from a powerful source of radio waves.
X Lock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driver's door
handle from close range and press the 0036or0037 button. There is a malfunction with KEYLESS-GO.
X Lock/unlock the vehicle using the remote control function of
the SmartKey. Point the tip of the SmartKey at the driver's door
handle from close range and press the 0036or0037 button.
X Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
X Check the SmartKey battery (Y page 83) and replace it if nec-
essary (Y page 83).
X Lock (Y page 88) or unlock (Y page 88) the vehicle using the
mechanical key. You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist work-
shop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. SmartKey
85Opening and closing Z

Problem
Possible causes/consequences and
0050
0050Solutions The engine cannot be
started using the
SmartKey. The on-board voltage is too low.
X Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 389).
or
X Jump-start the vehicle (Y page 391).
or
X Consult a qualified specialist workshop. The engine cannot be
started using KEYLESS-
GO. The SmartKey is in
the vehicle. A door is open. Therefore, the SmartKey cannot be detected as
easily.
X Close the door and try to start the vehicle again. There is interference from a powerful source of radio waves.
X Start your vehicle with the SmartKey in the ignition lock. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
If persons, particularly children are subjected to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle. G
WARNING
If objects, luggage or loads are not secured or not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
You should preferably place luggage or loads
in the cargo compartment. Observe the load- ing guidelines (Y page 334).86
DoorsOpening and closing

Problems with the seat ventilation
Problem
Possible causes/consequences and
0050
0050Solutions The seat ventilation has
switched off prema-
turely or cannot be
switched on. The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat ventilation will
switch back on automatically. Steering wheel
Important safety notes
G
WARNING
You could lose control of your vehicle if you do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt before starting the engine. G
WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never leave children unsupervised in the vehicle. Adjusting the steering wheel man-
ually
G
WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident. Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion.
0043
Release lever
0044 To adjust the steering wheel height
0087 To adjust the steering wheel position
(fore-and-aft adjustment)
X Push release lever 0043down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever 0043up completely.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. Steering wheel
111Seats, steering wheel and mirrors Z

Display messages
Possible causes/consequences and
0050
0050Solutions Wiper malfunction‐
Wiper malfunction‐
ing ing The windshield wipers are malfunctioning.
X Visit a qualified specialist workshop. Hazard warning
Hazard warning
lamps malfunction‐ lamps malfunction‐
ing ing The hazard warning lamps are faulty.
X Visit a qualified specialist workshop. SmartKey
Display messages
Possible causes/consequences and
0050
0050Solutions 00AF
Key Does Not Key Does Not
Belong to Vehicle Belong to Vehicle You have put the wrong SmartKey in the ignition lock.
X Use the correct SmartKey. 00AF
Take Take
Your
YourKey
Keyfrom
from
Ignition
Ignition The SmartKey is in the ignition lock.
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 Replace
Key
KeyBattery
Battery The batteries of the KEYLESS-GO key are discharged.
X Change the batteries (Y page 83).00AF
Don't Forget Your Don't Forget Your
Key Key This display message is displayed for a maximum of 60 seconds
and is simply a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.
X Remember to take the KEYLESS-GO key with you when you
leave the vehicle. 00AF
Key Not Detected Key Not Detected
(red display message) The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.
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 182).
X Locate the KEYLESS-GO key. Display
messages
317On-board computer and displays Z