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Turn Signal Indicator Actuation, Function - GF82.10-P-3008FR

Model 257, 290 

up to model year 2021 

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).

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

Function requirements, general 

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 front SAM control unit (N10/6). 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.

The turn signal light actuation encompasses the following partial functions:

The currently active function is indicated to the driver by the left turn signal light control message or the right turn signal light control message. For acoustic feedback, the instrument cluster (A1) actuates the instrument cluster speaker (H4/61). In order to do this, the instrument cluster receives the flasher frequency sent by the front SAM control unit over the interior CAN, the electronic ignition lock control unit (N73) and the user interface CAN (CAN HMI). If a turn signal light or a turn signal lamp fails, the frequencies with which the turn signal light control message and the instrument cluster speaker are actuated double. The flashing frequencies of the turn signal lights and turn signal lamps remain at f = 1.5 Hz.

IMPORTANT The hazard warning flasher can be overridden by the turn signaling function and vice versa.

IMPORTANT If in Economic Commission for Europe (ECE) vehicles, the turn signal is activated while the daytime running lights are actuated, the daytime running lights are dimmed to position light level (approx. 10 %). The turn signal light and daytime running light are actuated in alternate fashion.

IMPORTANT Model 257, 290

up to model year 2021

with code 460 (Canada version)

Model 257, 290

up to model year 2021

with code 494 (US version)

If the turn signals are used during daytime running lights actuation, the daytime running lights are switched off and only the turn signal light is actuated.

IMPORTANT Model 257, 290

up to model year 2021

with code 235 (Active Parking Assist)

Model 257, 290

up to model year 2021

with code 503 (Remote-controlled parking)

The Parking Pilot and Remote Parking Pilot functions can request turn signaling or override manually set turn signals.

IMPORTANT Model 257, 290

up to model year 2021

with code 23P (Drive package)

The Steering Pilot can extend a driver-initiated turn signal or one-touch turn signaling. It can also re-request turn signaling if the driver previously signaled in the same direction within the last 10 s.

Additional function requirements for turn signaling 

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

Function sequence for turn indicators 

The turn signaling function comprises the following subfunctions:

Function sequence, left turn signaling 

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

The steering column tube module control unit (N80) directly reads in the switch position of the combination switch and sends it to the front SAM control unit via the chassis FlexRay (Flex E), electronic ignition lock control unit and interior CAN.

The front SAM control unit receives the switch position of the combination switch and transmits the "Left turn signal" (flasher frequency) request to the following control units:

The left headlamp control unit receives the flasher frequency and actuates the front left turn signal light (E1e5) in the front left lamp unit directly.

The left front door control unit receives the flasher frequency and actuates the left outside mirror turn signal lamp (E6/5) directly.

The rear SAM control unit receives the flasher frequency and actuates the following components in the left rear lamp unit (E3) directly:

On vehicles with CODE 550 (Trailer hitch), the trailer recognition control unit receives the flasher frequency and actuates the left turn signal light on the trailer via the trailer socket (X58).

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

Function sequence, right turn signaling 

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

The steering column tube module control unit reads in the switch position of the combination switch directly and sends it via chassis FlexRay, the electronic ignition lock control unit and interior CAN to the front SAM control unit.

The front SAM control unit receives the switch position of the combination switch and transmits the "Right turn signal" (flasher frequency) request to the following control units:

The right headlamp control unit receives the flasher frequency and actuates the front right turn signal light (E2e5) in the front right lamp unit directly.

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

The rear SAM control unit receives the flasher frequency and actuates the following components in the right rear lamp unit (E4):

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.

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

Function sequence, one-touch turn signaling 

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 then output by the front SAM control unit. The one-touch turn signaling function is overridden when the hazard warning flasher function is actuated or the combination switch is activated 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.

However, all the turn signal lights and turn signal lamps on the vehicle are actuated synchronously.

As well as the control messages in the instrument cluster, the front SAM control unit actuates the indicator lamp in the hazard warning system button (N72/1s57) in the upper control panel control unit (N72/1) directly.

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

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

The hazard warning flasher function comprises the following subfunctions:

Function sequence for hazard warning flashing, manual 

The manual hazard warning flasher function is activated by pressing the hazard warning system button.

The front SAM control unit reads in the status of the hazard warning system button directly and then initiates the hazard warning flashing function by issuing the flasher frequency.

Following this, all turn signal lights and turn signal lights on the vehicle are actuated synchronously.

The front SAM control unit also actuates the indicator lamp in the hazard warning system button.

Additional function requirements for hazard warning flasher after emergency braking (except code 494 (USA version) and except code 460 (Canada version)) 

Function sequence for hazard warning flasher after emergency braking (except code 494 (USA version) and except code 460 (Canada version)) 

In the event of an emergency braking situation, the Electronic Stability Program control unit (N30/4) sends the "Emergency braking situation" (emergency braking) signal via the suspension FlexRay, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

If the vehicle was then decelerated below a speed v = 3 km/h, the front SAM control unit activates the hazard warning flasher function by issuing the flasher frequency. Following this, all turn signal lights and turn signal lights on the vehicle are actuated synchronously.

The Electronic Stability Program control unit transmits the vehicle speed via the chassis FlexRay, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

The hazard warning flasher is deactivated by pressing the hazard warning system button or upon exceeding a speed v = 10 km/h.

Additional function requirements for hazard warning flasher during emergency stop (with code 23P (Driving Assistance package)) 

Function sequence for hazard warning flasher during emergency stop (with code 23P (Driving Assistance package)) 

During an emergency stop executed by the Active Emergency Stop Assist function, the Mercedes-Benz Intelligent Drive control unit (N62/4) sends the "emergency stop" signal via the suspension FlexRay, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

The Electronic Stability Program control unit transmits the vehicle speed via the chassis FlexRay, the electronic ignition lock control unit and the interior CAN to the front SAM control unit.

As soon as the vehicle decelerates below a speed v = 60 km/h due to an emergency stop, the front SAM control unit activates the hazard warning flasher function by issuing the flasher frequency. Following this, all turn signal lights and turn signal lights on the vehicle are actuated synchronously.

As long as the speed does not fall below v = 3 km/h, the hazard warning flasher function is switched off when the "emergency stop" signal is canceled. If the speed falls below the threshold of v = 3 km/h, the hazard warning flasher function continues to be executed regardless of the status of the "emergency stop" signal.

The hazard warning flasher is then only terminated if the hazard warning system button is actuated with the "emergency stop" signal not being set or if a speed v = 10 km/h is exceeded.

The hazard warning flasher during emergency stop function is not available in the following countries:

Additional function requirements for hazard warning flasher when airbag deployed 

Function sequence for hazard warning flasher when airbag deployed 

When an airbag is deployed or during a rollover of the vehicle, the supplemental restraint system control unit (N2/10) sends the crash signal via the user interface CAN, electronic ignition lock control unit and interior CAN as well as 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. Following this, all turn signal lights and turn signal lights on the vehicle are actuated synchronously.

Operation of the hazard warning system button or unlocking of the central locking (CL) system terminates the hazard warning flasher.

The front SAM control unit directly reads in the status of the hazard warning system button.

The electronic ignition lock control unit sends the status of the central locking to the front SAM control unit via the interior CAN.

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

When the central locking system is locked/unlocked, the electronic ignition lock control unit requests the hazard warning flashing function. 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.

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

When an ATA alarm is triggered, the front SAM control unit initiates the hazard warning flashing function by issuing the flasher frequency.

Following this, all turn signal lights and turn signal lights on the vehicle are actuated synchronously.

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