Mercedes-Benz GLS Owner's Manual page 459

456 Display messages and warning/indicator lamps
Display messages
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Trailer coupling extending...
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Check trailer hitch lock
Possible causes/consequences and
* The ball neck is retracting/extending.
Do not attempt to speed up, slow down or initiate the swivel movement using your hand, foot or other aids. During
the swivel movement, do not couple a trailer.
When the ball neck has reached an operational position, the display message will disappear.
* The trailer hitch is not operational during a journey with a trailer.
& WARNING Risk of an accident if the ball neck is not locked
The trailer may become detached.
Stop the vehicle immediately in accordance with the traffic conditions. Do not continue driving.
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Uncouple the trailer and secure it against rolling away.
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Initiate a new swivel movement and do not re-couple the trailer until the warning/indicator lamp goes out.
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Initiate a new swivel movement (
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When the display message disappears, couple up the trailer and drive on.
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If the display message does not disappear, the trailer hitch is malfunctioning and the ball neck is not locked.
Do not couple up the trailer. Drive on without the trailer. Note the reduced ground clearance due to the
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unlocked ball neck.
Consult a qualified specialist workshop.
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* The trailer hitch will not be operational when the vehicle is stationary.
M M Solutions
page 301).
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