Problems with the SmartKey

Problem Possible causes/consequences and Solutions
You cannot lock or unlock the vehicle using the SmartKey. The SmartKey battery is discharged or nearly discharged.
- 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 button./button. button.
If this does not work:
- Check the SmartKey battery and replace it if necessary.
- Lock or unlock the vehicle using the mechanical key.
The SmartKey is faulty.
- Lock or unlock the vehicle using the mechanical key.
- 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.
- 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 button./button. button.
There is a malfunction with KEYLESS-GO.
- 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 button./button. button.
- Have KEYLESS-GO checked at a qualified specialist workshop.
If this does not work:
- Check the SmartKey battery and replace it if necessary.
- Lock or unlock the vehicle using the mechanical key.
You have lost a SmartKey. - Have the SmartKey deactivated at a qualified specialist workshop.
- Report the loss immediately to the vehicle insurers.
- If necessary, have the locks changed as well.
You have lost the mechanical key. - Report the loss immediately to the vehicle insurers.
- If necessary, have the locks changed as well.
The engine cannot be started using the SmartKey. The on-board voltage is too low.
- Switch off non-essential consumers, e.g. seat heating or interior lighting, and try to start the engine again.
If this does not work:
- Check the starter battery and charge it if necessary.
or
- Jump-start the vehicle.
or
- 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.
- Close the door and try to start the vehicle again.
There is interference from a powerful source of radio waves.
- Start your vehicle with the SmartKey in the ignition lock.
    See also:

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