Turn signal indicator actuation, function - GF82.10-P-3008FQ

MODEL 218 

Information on equipment variants 

The following list includes all possible versions of the left front lamp unit (E1) and the right front lamp unit (E2).

To improve the readability of this function description, the following text does not reference the comprehensive equipment codes. Instead, signal words are used that create an association with the equipment cited.

The following variants of the front lamp units are offered, depending on the vehicle equipment:

• Lamp units in xenon version (up to 31.08.2014) 

  (Without code (621) Intelligent Light System (left-hand traffic) and without code (622) Intelligent Light System (right-hand traffic))

• Lamp units in full LED version (dynamic up to 31.08.2014) 

  (with code (621) Intelligent Light System (left-hand traffic) or code (622) Intelligent Light System (right-hand traffic))

• Lamp units in full LED version (static as of 01.09.2014) 

  (With code (631) Full LED headlamp (without ILS), daytime running lamps integrated in headlamp, for left-hand traffic or code (632) Full LED headlamp (without ILS), daytime running lamps integrated in headlamp, for right-hand traffic)

• Lamp units in full LED version (dynamic as of 01.09.2014) 

  (With code (640) Full LED for U.S.A. incl. ACTIVE MULTIBEAM LED or code (641) Full LED headlamp incl. ILS and ACTIVE MULTIBEAM LED (USP!) incl. new light design, dynamic LED for left-hand traffic or code (642) Full LED headlamps incl. ILS and ACTIVE MULTIBEAM LED (USP!) incl. new light design, dynamic LED for right-hand traffic)

Function requirements, general 

• No overvoltage or undervoltage (on-board electrical system voltage U ≥7 ≤17.5 V)

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 turn signal functions is the front SAM control unit with fuse and relay module (N10/1). The front SAM control unit prioritizes all flashing requests and transmits a flasher frequency with a time period of the bright phase of the turn signal lamps over the interior CAN (CAN B) to the corresponding control units.

Each active function is signaled to the driver by actuating the left turn signal light indicator lamp (A1e1) or the right turn signal light indicator lamp (A1e2) and the acoustic turn signal light function check (A1h2). For this purpose, the instrument cluster (A1) receives the flasher frequency transmitted by the front SAM control unit via interior CAN.

If a turn signal light or turn signal lamp fails, the frequency of the turn signal light indicator lamps and the acoustic turn signal light function check in the instrument cluster doubles.

The flashing frequency of the turn signal indicators of f = 1.5 Hz remains.

Substitute lamp actuation: 

When the left rear turn signal light (E3e1) in the left rear lamp unit (E3) fails, the left brake light, taillight, and parking light (E3e9) are actuated, and when the right rear turn signal light (E4e1) in the right rear lamp unit (E4) fails, the right brake light, taillight, and parking light (E4e9) are actuated.

Lamp units in full LED version (dynamic as of 01.09.2014) 

When the turn signal is activated during daytime running lights actuation on Economic Commission for Europe (ECE) vehicles, the daytime running light in the left position light, daytime running light, turn signal light, and ambient light (E1e26) and the daytime running light in the right position light, daytime running light, turn signal light, and ambient light (E2e26) are dimmed to position light level (approximately 10 %). The turn signal light and daytime running light are actuated in alternate fashion.

If on vehicles with code (460) Canada version or code (494) USA version, the turn signal is activated during daytime running lights actuation, the daytime running lights actuation is suspended and only the turn signal light in the left position light, daytime running light, and turn signal light (E1e25) and the turn signal light in the right position light, daytime running light, and turn signal light (E2e25) are actuated.

The turn signal light actuation encompasses the following partial functions:

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

Additional function requirements for turn signaling 

• Circuit 15R ON

The electronic ignition lock control unit (N73) sends the status of circuit 15 to the front SAM control unit via interior CAN.

Function sequence for turn indicators 

The turn signaling function comprises the following subfunctions:

• Function sequence, left turn signal indicator 
• Function sequence for right turn signal indicator 
• Function sequence, touch turn signal indicator 

Function sequence, left turn signal indicator 

The left turn signal function is requested by pushing the combination switch (S4) downward.

The steering column tube module control unit (N80) reads in the switch position of the combination switch directly and sends this via chassis CAN (CAN E) (up to 28.02.2013) or chassis CAN 1 (CAN E1) (as of 01.03.2013) to the front SAM control unit. The front SAM control unit evaluates the switch position of the combination switch and sends the request to output the left turn signal function as a flasher frequency via the interior CAN to the control units that are connected to the interior CAN.

Vehicles up to 31.08.2014: 

The front SAM control unit actuates the left front turn signal light (E1e5) via the left front actuation module 1, LED exterior lighting (E1n7).

Vehicles as of 01.09.2014: 

The front SAM control unit sends the flasher frequency via the chassis CAN 2 (CAN E2) to the left headlamp control unit (E1n9).

The left headlamp control unit then actuates the left front turn signal light (lamp units in full LED version (static)) or the turn signal light in the left position light, daytime running light, turn signal light, and ambient light (ECE vehicles only) or the turn signal light in the left position light, daytime running light, and turn signal light (not ECE vehicles) (lamp units in full LED version (dynamic)).

The rear SAM control unit with fuse and relay module (N10/2) receives the flasher frequency, and actuates the left rear turn signal light on vehicles up to 31.08.2014 and as of 01.09.2014 without code (460) Canada version and without code (494) USA version. On vehicles as of 01.09.2014 with code (460) Canada version or code (494) USA version, the rear SAM control unit actuates the left brake light (E3e4). The left front door control unit (N69/1) receives the flasher frequency and actuates the left outside mirror turn signal lamp (E6/5).

In vehicles with code (550) Trailer hitch, the trailer recognition control unit (N28/1) receives the flasher frequency and actuates the left turn signal light on the trailer via the trailer socket (X58).

Function sequence for right turn signal indicator 

The right turn signal function is requested by pressing the combination switch upward.

The steering column tube module control unit reads in the switch position of the combination switch directly and sends this via chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) to the front SAM control unit. The front SAM control unit evaluates the switch position of the combination switch and sends the request to output the right turn signal function as a flasher frequency via the interior CAN to the control units that are connected to the interior CAN.

Vehicles up to 31.08.2014: 

The front SAM control unit actuates the right front turn signal light (E2e5) via the right front actuation module 1, LED exterior lighting (E2n7).

Vehicles as of 01.09.2014: 

The front SAM control unit sends the flasher frequency via the chassis CAN 2 to the right headlamp control unit (E2n9).

The right headlamp control unit actuates the right front turn signal light (lamp units in full LED version (static)) or the turn signal light in the right position light, daytime running light, turn signal light, and ambient light (ECE vehicles only) or the turn signal light in the right position light, daytime running light, and turn signal light (not ECE vehicles) (lamp units in full LED version (dynamic)).

The rear SAM control unit receives the flasher frequency, and actuates the right rear turn signal light on vehicles up to 31.08.2014 and as of 01.09.2014 without code (460) Canada version and without code (494) USA version. On vehicles as of 01.09.2014 with code (460) Canada version or code (494) USA version, the rear SAM control unit actuates the right brake light (E4e4).

The right front door control unit (N69/2) receives the flasher frequency and actuates the right outside mirror turn signal lamp (E6/6).

In vehicles with code (550) Trailer hitch, the trailer recognition control unit receives the flasher frequency and actuates the right turn signal light on the trailer over the trailer socket.

Function sequence, touch turn signal indicator 

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

To trigger the touch turn signaling function, the combination switch must only be pressed briefly (t < 440 ms) in the desired turn signal direction.

Three flashing cycles are output by the front SAM control unit. The touch turn signaling function is interrupted by means of actuation of the hazard warning flasher function or activation of the combination switch in the opposite direction.

Function sequence, hazard warning flashing 

The function sequence for the hazard warning flasher is identical to that for turn signaling in terms of signal flow.

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

In addition to the displays in the instrument cluster, the indicator lamp in the hazard warning flasher switch (N72/1s5) in the upper control panel control unit (N72/1) is actuated by the front SAM control unit via the instrument panel LIN (LIN 1).

Depending on the status of circuit 15, two duty cycles are output by the front SAM control unit:

• With circuit 15R On: light 58 %, dark 42 %
• With circuit 15R Off: light 35 %, dark 65 %

If the failure of a turn signal light or a turn signal lamp is detected during hazard warning flashing, the frequency of the turn signal light indicator lamps and the acoustic turn signal light function check does not double.

The hazard warning flasher function comprises the following subfunctions:

• Function sequence for hazard warning flashing, manual 
• Function sequence, hazard warning flashing after emergency braking 
• Function sequence for hazard warning flasher when airbag deployed 
• Function sequence for hazard warning flashing in the event of crash detection (serious accident) 
• Function sequence, feedback from locking/unlocking of central locking (CL) 
• Function sequence, antitheft alarm system (ATA) flashing (with code (551) Antitheft alarm system (ATA)) 

Function sequence for hazard warning flashing, manual 

The manual hazard warning flasher function is activated by pressing the hazard warning flasher switch in the upper control panel control unit.

The front SAM control unit reads in the status of the hazard warning flasher switch via the instrument panel LIN and activates the hazard warning flasher function by issuing the flasher frequency.

All turn signal indicators are then actuated synchronously on the vehicle.

Additional function requirements, hazard warning flashing after emergency braking 

• Circuit 15 On (transmitted by the electronic ignition lock control unit via the interior CAN)
• Emergency braking detected within t = 500 ms (vehicle speed v > 70 km/h and Brake Assist System active or vehicle deceleration a > 7.5 m/s² )

Function sequence, hazard warning flashing after emergency braking 

In the event of emergency braking, the Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS and without engine 157) or the Premium Electronic Stability Program control unit (N30/7) (with code (233) DISTRONIC PLUS or with engine 157) sends the "Emergency braking" signal via the chassis CAN (up to 28.02.2013) or the chassis CAN 1 (as of 01.03.2013) to the front SAM control unit. If the vehicle was decelerated below a speed of v = 3 km/h during the emergency braking maneuver, the front SAM control unit activates the hazard warning flasher function for emergency braking by issuing the flasher frequency. All turn signal indicators are then actuated synchronously on the vehicle.

The instrument cluster sends the vehicle speed to the front SAM control unit over the interior CAN.

This function is deactivated by pressing the hazard warning flasher switch or upon exceeding a speed of v = 10 km/h.

Additional function requirements for hazard warning flasher when airbag deployed 

• Deceleration a > 4 g

Function sequence for hazard warning flasher when airbag deployed 

When an airbag is deployed, the Supplemental Restraint System control unit (N2/10) sends the crash signal via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) and also via a direct line to the front SAM control unit. The front SAM control unit then initiates the hazard warning flasher function by issuing the flasher frequency. All turn signal indicators are then actuated synchronously on the vehicle.

This function is deactivated by pressing the hazard warning flasher switch or by globally unlocking the central locking.

Additional hazard warning flashing function requirements in the event of crash detection (serious accident) 

• Deceleration a > 6 g

Function sequence for hazard warning flashing in the event of crash detection (serious accident) 

A crash sensor is integrated in the front SAM control unit. If this detects a crash event during a timeout period of the Supplemental Restraint System control unit, the front SAM control unit initiates the hazard warning flasher function by outputting the flasher frequency. This serves to avoid any inadvertent activation of the local crash sensor. All turn signal indicators are then actuated synchronously on the vehicle.

This function is deactivated by pressing the hazard warning flasher switch or by globally unlocking the central locking.

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

The hazard warning flasher function is executed when locking/unlocking the CL [ZV]. To this end, the electronic ignition lock control unit sends the status of the central locking over interior CAN to the front SAM control unit.

The front 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.

Acoustic feedback also occurs in accordance with the flashing cycles by means of actuating the left horn (H2) and right horn (H2/1).

Function sequence for ATA flashing (with code (551) Anti-theft alarm system (ATA) [EDW]) 

When an ATA [EDW] alarm is triggered, the rear SAM control unit requests the hazard warning flashing function via interior CAN.

The request must be transmitted cyclically so that the flasher frequency results from the bright time and the cycle time.

The front SAM control unit receives the request, generates a corresponding flasher frequency, and sends this to the respective control units. All turn signal indicators are then actuated synchronously on the vehicle.

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