Turn Signals: Description and Operation

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

Component Identification:

Function requirements:
^ Circuit 15 ON
^ Combination switch (S4) in "Left or right turn signal" position

Function
The steering column module (N80) detects the position of the combination switch (S4) and sends the "flash to the left" or "flash to the right" message to the relevant control units via the class B (interior) Controller Area Network Bus (CAN-B) to actuate the turn signal lamps.

Left turn signal
The steering column module (N80) reads in the position of the combination switch (S4) "flash to the left" and transmits the message via the CAN-B to the rear SAM control unit with fuse and relay module (N10/2). This actuates the left turn signal lamp (E3e1) in the left taillamp (E3).

The "flash to the left" message is simultaneously transmitted via the CAN-B to the left door control unit (N69/1) and the front SAM control unit with fuse and relay module (N10/1). The left door control unit (N69/1) actuates the left outside mirror turn signal lamp (E6/5). The front SAM control unit with fuse and relay module (N10/1) actuates the left turn signal lamp (E1e5).

Right turn signal
The steering column module (N80) reads in the position of the combination switch (S4) "flash to the right" and transmits the message via the CAN-B to the rear SAM control unit with fuse and relay module (N10/2). This actuates the right turn signal lamp (E4e1) in the right taillamp (E4).

The "flash to the right" message is simultaneously transmitted via the CAN-B to the right door control unit (N69/2) and the front SAM control unit with fuse and relay module (N10/1). The right door control unit (N69/2) actuates the right outside mirror turn signal lamp (E6/6). The front SAM control unit with fuse and relay module (N10/1) actuates the right turn signal lamp (E2e5).

The following indicator lamps are activated as a visual indicators in the instrument cluster (A1).
^ Left turn signal indicator lamp (A1e1)
^ Right turn signal indicator lamp (A1e2)
^ The audible turn signal indicator (A1h2)

Turn signal flashing is automatically ended by automatic reset due to countersteering or by manual reset of the combination switch (S4).
If a turn signal lamp malfunctions, the flashing frequency of the left turn signal indicator lamp (A1e1) or right turn signal indicator lamp (A1e2) doubles only in the instrument cluster (A1).

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 is only how the flashing operation is actuated and terminated.
For the touch turn signal mode the combination switch lever (S4) should only be briefly moved (less than 500 ms) into the desired signaling position. Without the lever 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 flasher function or operating the combination switch (S4) in the opposite direction.

In vehicles with code (550) Trailer hitch, the "flash to the left" or "flash to the right" message is transmitted by the rear SAM control unit with fuse and relay module (N10/2) to the trailer recognition control unit (N28/1), which actuates the 13-pin trailer hitch socket (X58).