Mercedes-Benz B-Class 2011 Owner's Manual page 78

Problems with the key
Problem
You cannot lock or
unlock the vehicle
using the key.
You have lost a key.
You have lost the emer-
gency key element.
The engine cannot be
started using the key.
The engine cannot be
started using the key.
Possible causes/consequences and M Solutions
The key battery is discharged or nearly discharged.
Try again to lock/unlock the vehicle using the remote control
X
function of the key. Point the tip of the key at the driver's door
handle from close range and press the % / & button.
If this does not work:
Check the key battery and replace it if necessary (
X
Lock ( page 77) or unlock (
X
Y
the emergency key element.
The key is faulty.
Lock ( page 77) or unlock (
X
Y
the emergency key element.
Have the key checked at a qualified specialist workshop.
X
Have the key deactivated at a qualified specialist workshop.
X
Report the loss immediately to the vehicle insurers.
X
If necessary, have the locks changed as well.
X
Report the loss immediately to the vehicle insurers.
X
If necessary, have the locks changed as well.
X
The on-board voltage is too low.
Switch off non-essential consumers, e.g. seat heating or interior
X
lighting, and try to start the engine again.
If this does not work:
Check the starter battery and charge it if necessary
X
( page 280).
Y
or
Jump-start the vehicle (
X
or
Consult a qualified specialist workshop.
X
The steering lock is mechanically blocked.
Remove the key and reinsert it into the ignition lock. While doing
X
this, turn the steering wheel in both directions.
page 78) the vehicle using
Y
page 78) the vehicle using
Y
page 283).
Y
Key
75
page 74).
Y
Z