How do you reset Mercedes GL350 cdi adblue warning?

To reset the AdBlue warning on a Mercedes GL350 CDI, first ensure that the AdBlue tank is filled with the appropriate fluid. Then, turn the ignition to the "On" position without starting the engine. Press the gas pedal three times within ten seconds to reset the warning. If the warning persists, you may need to use a diagnostic tool or consult a dealership for assistance.