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Turn Signals
To engage a turn signal, press the corresponding arrow button on the left side of the steering yoke. A turn signal cancels based on the angle of the steering yoke (for example, you finish making a turn). You can also cancel a turn signal by pressing the turn signal button a second time.
If Controls > Pedals & Steering > Automatic Turn Signals is set to Auto Cancel, turn signals cancel automatically when Model S detects completion of a maneuver such as a merge, lane change, or a fork in the roadway. You can override automatic cancellation at any time (for example, you want the turn signal to remain on because you are making more than one lane change). To override, engage the turn signal by pressing and momentarily holding the turn signal button (instead of just pressing). Then, when the first maneuver is complete, the turn signal remains on. If Automatic Turn Signals is set to Off, you must cancel the turn signal manually by pressing the turn signal button after maneuvers such as a merge, lane change, or fork in the roadway.
I. E. If NOT set to Auto Cancel, the signal cancels by yoke angle. If the signal IS set to Auto Cancel, a simple lane change will turn it off automaticaly, but an overide to stay on longer requires one to hold the signal down longer..