Turn Signals: Description and Operation

GF82.10-P-3008TX Turn Signal Lamp Actuation, Function

Component Identification:

Function requirements
^ Circuit 5R On

Function
The steering column module detects the position of the turn signal indicator switch and over CAN-B sends the "Indicating to left" or "Indicating to right" signal to the rear SAM control unit.
The rear SAM control unit is the master control unit for all indicating functions and forwards the corresponding signals over CAN-B to the corresponding control units.

Left turn signal
The driver-side SAM control unit actuates the turn signal lamp in the left front lamp unit (E1).
The left front door control unit actuates the left outside mirror turn signal lamp.
The rear SAM control unit actuates the turn signal lamp in the left taillamp (E3).

Right turn signal
The front passenger-side SAM control unit actuates the turn signal lamp in the right front lamp unit (E2).
The right front door control unit actuates the right outside mirror turn signal lamp.
The rear SAM control unit actuates the turn signal lamp in the right taillamp (E4).

Feedback
In the instrument cluster for visual feedback, the corresponding indicator lamp is actuated.
For acoustic feedback, the turn signal indicator in the instrument cluster is activated.
If a turn signal lamp malfunctions, the flashing frequency is doubled for the particular indicator lamp in the instrument cluster.

Actuation of the turn signals is terminated automatically by means of automatic reset when the steering wheel is turned back or by manually moving the turn signal indicator switch to the middle position.

Operational sequence turn signal lamp touch control
The operational sequence for the turn signal lamp touch control is the same, in relation to the signal flow, as that for the turn signal indicator. The difference lies in the actuation and termination of the turn signal procedure.

For one-touch turn signaling mode the turn signal indicator switch should only be briefly moved (approx. 0.5 ms) into the desired signaling position. Without the turn signal indicator switch engaging into place in the signaling position a sequence of three turn-signal cycles is triggered.
One-touch turn signaling is interrupted by activating the hazard warning lamp function or by operating the turn signal indicator switch in the opposite direction.