Turn Signal Indicator Actuation, Function - GF82.10-S-3008TRF

Model 447 

with code XM0 (Facelift) 

except code XM7 (MOPF II) 

Function requirements, general 

• No overvoltage or undervoltage

Turn signal light actuation, general 

The turn signal light actuation consists of all functions for output of the turn signal, various warnings and feedback.

The master control unit for all flashing functions is the signal acquisition and actuation module (SAM) control unit (N10/1). It prioritizes all turn requests and sends a flasher frequency with duration of illumination time for the turn signal lamps.

Each active function is shown to the driver by the left turn signal indicator lamp (A1/1e1) or the right turn signal indicator lamp (A1/1e2) visually in the instrument cluster (IC [KI]) control unit (A1/1). Visual and acoustic feedback is only issued when the instrument cluster (IC [KI]) control unit is active.

If turn signal light actuation has been activated, the front daytime running lights of the relevant side are deactivated.

If a turn signal lamp fails, the frequencies of the turn signal indicator lamps and the instrument cluster speaker are doubled. The flashing frequency of the turn signal lamps of 1.5 Hz is retained.

Model 447.6/7

For acoustic feedback the instrument cluster (IC [KI]) control unit actuates the instrument cluster speaker (H4/61). For this purpose, it receives the flasher frequency sent by the signal acquisition and actuation module (SAM) control unit via the interior CAN.

Model 447.8

For acoustic feedback the instrument cluster (IC [KI]) control unit actuates the instrument cluster speaker. For this purpose, it receives the flasher frequency sent by the signal acquisition and actuation module (SAM) control unit via the interior CAN (CAN B), electronic ignition lock control unit (EZS) (N73), chassis CAN (CAN E), central gateway (N93/4), and user interface CAN (CAN HMI).

The turn signal light actuation encompasses the following partial functions:

• Function sequence for turn indicators
• Function sequence, hazard warning flashing

Function sequence for turn indicators 

Additional function requirements for turn signaling:

• "Circuit 15 ON"

The circuit status of circuit 15 is sent by the electronic ignition lock control unit (EZS) via the interior CAN to the signal acquisition and actuation module (SAM) control unit.

The turn signaling function encompasses the following subfunctions:

• Function sequence for left and right turn signals
• Function sequence for one-touch turn signaling

Function sequence for left and right turn signals 

Pressing the combination switch (S4) downward for left or upward for right requests the turn signaling function.

The steering column tube module (MRM) control unit (N80) reads in the turn signaling request directly. It sends this via the chassis CAN, electronic ignition lock control unit (EZS), and interior CAN to the signal acquisition and actuation module (SAM) control unit.

On model 447.6/7: 

The signal acquisition and actuation module (SAM) control unit receives the turn signaling request. It sends the corresponding actuation of the turn signal lamps to the left additional turn signal lamp (E22/1) or right additional turn signal lamp (E22/2).

On Model 447.8: 

The signal acquisition and actuation module (SAM) control unit receives the turn signaling request and sends the corresponding actuation of the turn signal lamps to the following control units and components:

• Via the interior CAN to the left front door control unit (N69/3), which then directly actuates the left outside mirror turn signal lamp (M21/4e1) installed in the left outside mirror (M21/4).
• Via the interior CAN to the right front door control unit (N69/4), which then directly actuates the right outside mirror turn signal lamp (M21/5e1) installed in the right outside mirror (M21/5).

The signal acquisition and actuation module (SAM) control unit sends the turn signal lamps actuation to the following control units and components:

On vehicles without CODE LG2 (LED Intelligent Light System): 

• Directly via the front left lamp unit (E1) to the front left turn signal light (E1e5)
• Directly via the front right lamp unit (E2) to the front right turn signal light (E2e5)
• Directly over the left rear lamp unit (E3) to the left rear turn signal light (E3e1)
• Directly over the right rear lamp unit (E4) to the right rear turn signal light (E4e1)

On vehicles with CODE LG2 (LED Intelligent Light System): 

• Via the interior CAN, electronic ignition lock control unit (EZS), front end CAN (CAN G), left headlamp control unit (E1/1n9) to the actuation module for the front left LED exterior lighting (E1/1 n7). This then directly actuates the front left turn signal light (E1/1e5).
• Via the interior CAN, electronic ignition lock control unit (EZS), front end CAN, right headlamp control unit (E2/1 n9) to the actuation module for the front right LED exterior lighting (E2/1 n7). This then directly actuates the front right turn signal light (E2/1e5).
• Directly over the left rear LED lamp unit (E31) to the left rear turn signal light (E31e1)
• Directly over the right rear LED lamp unit (E41) to the right rear turn signal light (E41e1)

On vehicles with CODE Q50 (Trailer hitch with removable ball head) or CODE Q22 (Trailer hitch with non-removable ball head): 

The trailer recognition control unit (AAG) (N28/1) receives the flasher frequency signal from the signal acquisition and actuation module (SAM) control unit via the interior CAN. It actuates the relevant turn signal light on the trailer via the 13-pin trailer socket (X58).

The left or right turn signal can be overridden by the hazard warning flasher 'function, and vice versa.

Function sequence for one-touch turn signaling 

With regard to signal flow, the function sequence of the one-touch turn signaling function corresponds to that of the left and right turn signal function. The difference is in the triggering and ending of the turn signal procedure.

To activate the one-touch turn signaling function, the combination switch must simply be briefly (less than 440 ms) actuated in the desired turn signal direction.

Three flasher cycles are then issued by the signal acquisition and actuation module (SAM) control unit.

The one-touch turn signaling function is overridden when the hazard warning light function is actuated or terminated when the combination switch is actuated in the opposite direction.

Function sequence, hazard warning flashing 

The hazard warning flasher function sequence is the same as that for turn signaling with regard to the signal flow.

All turn signal lamps on the vehicle are actuated synchronously, however.

Two duty cycles are issued by the signal acquisition and actuation module (SAM) control unit depending on the circuit status of circuit 15R:

• At "Circuit 15R ON": Bright 52 %, dark 48 %
• At "Circuit 15R OFF": Bright 35 %, dark 65 %

If the malfunction of a turn signal lamp is detected during hazard warning flashing, the frequencies of the turn signal indicator lamps and the instrument cluster speaker are not doubled.

The hazard warning flashing function encompasses the following subfunctions:

• Function sequence for hazard warning flashing, manual
• Function sequence for hazard warning flasher after emergency braking
• Function sequence for hazard warning flasher when airbag deployed
• Function sequence, feedback from locking/unlocking of central locking (CL)
• Function sequence for anti-theft alarm system (ATA [EDW]) flashing (with code FY1 (Theft protection package) or with code FZ5 (Anti-theft alarm system))

Function sequence for hazard warning flashing, manual 

The manual hazard warning flasher function is activated by pressing the following buttons:

On model 447.6/7: 

• Hazard warning light system button (N72/1s4) in upper control panel (UCP) control unit (N72/1)

The signal acquisition and actuation module (SAM) control unit reads in the status of the hazard warning system button directly; all turn signal lamps on the vehicle are then actuated synchronously.

The signal acquisition and actuation module (SAM) control unit also actuates the hazard warning light system indicator lamp (N72/1e4) in the hazard warning light system button.

On Model 447.8: 

• Hazard warning light system button (N72/2s6) in upper control panel (UCP) control unit (N72/2)

The signal acquisition and actuation module (SAM) control unit reads in the status of the hazard warning system button directly; all turn signal lamps on the vehicle are then actuated synchronously.

The signal acquisition and actuation module (SAM) control unit also actuates the hazard warning light system indicator lamp (N72/2e4) in the hazard warning light system button.

Function sequence for hazard warning flasher after emergency braking 

Additional function requirements:

• Circuit 15 ON status
• On model 447.8 with code ET4 (Active Distance Assist DISTRONIC): 

  Maximum full-stop braking detected within 500 ms (vehicle speed > 70 km/h and Brake Assist active)

• On model 447 without code ET4 (Active Distance Assist DISTRONIC): 

  Maximum full-stop braking detected within 500 ms (vehicle speed > 70 km/h and vehicle deceleration > 7.5 m/s² )

In the event of maximum full-stop braking, the Electronic Stability

Program (ESP) control unit (N30/4) sends the "Maximum full-stop braking" signal via the chassis CAN, electronic ignition lock control unit (EZS), and interior CAN to the signal acquisition and actuation module (SAM) control unit.

If the vehicle was then decelerated below a speed of 3 km/h, the signal acquisition and actuation module (SAM) control unit activates the "Hazard warning light" function.

The Electronic Stability Program (ESP) control unit transmits the vehicle speed via the chassis CAN, the electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.

Flashing is deactivated by pressing the hazard warning light system button or upon exceeding a speed of 10 km/h.

Function sequence for hazard warning flasher when airbag deployed 

If the airbag is deployed, the supplemental restraint system (SRS) control unit (N2/18) sends the "Crash flashing" request via the chassis CAN, electronic ignition lock (EZS) control unit and the interior CAN to the signal acquisition and actuation module (SAM) control unit.

The signal acquisition and actuation module (SAM) control unit then actuates the hazard warning flasher function.

Operation of the hazard warning system button or unlocking of the central locking (CL [ZV]) system terminates the flashing.

The central locking status is sent by the electronic ignition lock control unit (EZS) over the interior CAN to the signal acquisition and actuation module (SAM) control unit.

Function sequence, feedback from locking/unlocking of central locking (CL) 

When locking/unlocking the central locking system, the electronic ignition lock control unit (EZS) requests the hazard warning flasher function. To this end, the central locking status is sent by the electronic ignition lock control unit (EZS) over the interior CAN to the signal acquisition and actuation module (SAM) control unit.

The signal acquisition and actuation module (SAM) control unit activates the hazard warning flashing function for one flasher cycle when the central locking system is unlocked, and for three flasher cycles when the central locking system is locked.

A detailed description of this function can be found in the separate document "Central locking (CL [ZV]), function".

Function sequence for anti-theft alarm system (ATA [EDW]) flashing (with code FY1 (Theft protection package) or with code FZ5 (Anti-theft alarm system)) 

On vehicles with CODE FY1 (Theft protection package): 

When activating an ATA [EDW] alarm, the anti-theft alarm system (ATA [EDW]) control unit (N26/6) sends the "ATA [EDW] flashing" request via interior CAN to the signal acquisition and actuation module (SAM) control unit.

All the turn signal lights and turn signal lamps on the vehicle are then synchronously actuated by the signal acquisition and actuation module (SAM) control unit.

On vehicles with CODE FZ5 (Anti-theft alarm system): 

When an ATA [EDW] alarm is triggered, all the turn signal lights and turn signal lamps on the vehicle are then synchronously actuated by the signal acquisition and actuation module (SAM) control unit.

A detailed description of this function can be found in the separate document "Anti-theft alarm system (ATA [EDW]), function".

Overview of exterior lights system components

GF82.10-S-9998TRF