Perform function check on trailer hitch with electrical release
08.02.2019
Model
118, 177.0/1, 247
with code 550 (Trailer coupling)
Check
1
Switch on ignition.
2
Operate trailer hitch switch (S143/3) in liftgate until the ball neck is unlocked.
If the ball neck is not engaged, the light-emitting diode on the trailer hitch switch (S143/3) in the liftgate begins to flash. The warning message "Check trailer lock" appears on the instrument cluster.
3
Pull ball neck out until it latches into place.
The light-emitting diode on the trailer hitch switch (S143/3) goes out. The warning message in the instrument cluster disappears.