Mercedes-Benz C-CLASS CABRIOLET Operator's Manual page 81

Problems with the SmartKey
Problem
You can no longer lock or
unlock the vehicle using
the SmartKey.
You can no longer lock or
unlock the vehicle using
KEYLESS-GO.
The engine cannot be
started using the Smart-
Key.
Possible causes/consequences and M Solutions
The SmartKey battery is discharged or nearly discharged.
Check the SmartKey battery (
X
( page 78).
Y
If this does not work:
Lock or unlock the vehicle using the mechanical key (
X
There is interference from a powerful source of radio waves.
Lock or unlock the vehicle using the mechanical key (
X
The SmartKey is faulty.
Lock or unlock the vehicle using the mechanical key (
X
Have the SmartKey checked at a qualified specialist workshop.
X
KEYLESS-GO was deactivated.
Reactivate KEYLESS-GO (
X
The SmartKey battery is discharged or nearly discharged.
Check the SmartKey battery (
X
( page 78).
Y
If this does not work:
Lock or unlock the vehicle using the mechanical key (
X
There is interference from a powerful source of radio waves.
Lock or unlock the vehicle using the mechanical key (
X
KEYLESS-GO is malfunctioning.
Lock/unlock the vehicle using the remote control function of the
X
SmartKey.
Have the vehicle and SmartKey checked at a qualified specialist
X
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function:
Lock or unlock the vehicle using the mechanical key (
X
Have the vehicle and SmartKey checked at a qualified specialist
X
workshop.
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
or
Jump-start the vehicle (
X
or
Consult a qualified specialist workshop.
X
page 78) and replace it if necessary
Y
page 76).
Y
page 78) and replace it if necessary
Y
page 299).
Y
SmartKey
79
page 82).
Y
page 82).
Y
page 82).
Y
page 82).
Y
page 82).
Y
page 82).
Y
page 299).
Y
Z