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

Model 205, 253 

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.

IMPORTANT The respective active function is visually displayed to the driver via the left turn signal light indicator lamp (A1e1) or the right turn signal light indicator lamp (A1e2). The symbols of the indicator lamps are accordingly shown in the digital full display (with code 464 (Digital instrument cluster full display)). 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 frequency of the turn signal lights and turn signal lamps of 1.5 Hz continues to remain.

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

IMPORTANT Model 205 as of model year 2019

Model 253 (except 253.99) as of model year 2020

Model 253.99

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 205, 253 except code 498 (Japanese 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.

Model 205, 253 with code 235 (Parking Pilot with PARKTRONIC)

Model 205, 253 with code 503 (Pre-installation for Remote Parking Pilot)

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

IMPORTANT Model 205, 253 with code 23P (Driving Assistance 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. A differentiation is made between the following versions of the left front lamp unit (E1) and the right front lamp unit (E2) in accordance with the vehicle equipment:

The turn signal light actuation encompasses the following partial functions:

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 sends the "Left turn signal" (flasher frequency) over the interior CAN to the following control units:

On vehicles with halogen headlamps, the front SAM control unit actuates the left front turn signal light (E1e5) in the left front lamp unit directly.

For model 205, model 253 (except model 253.99) as of 01.06.2019 and model 253.99 (in each case with LED headlamps), the left headlamp control unit receives the flasher frequency and directly actuates the left front turn signal light.

For model 253 (except model 253.99) up to 31.05.2019 with LED headlamps (static), the left headlamp control unit receives the flasher frequency and directly actuates the turn signal light in the left perimeter light, daytime running light and turn signal light (E1e25).

For model 253 (except model 253.99) up to 31.05.2019 with LED headlamps (dynamic), the left headlamp control unit receives the flasher frequency and directly actuates the turn signal light in the left perimeter light, daytime running light and turn signal light (except Economic Commission for Europe (ECE) vehicles) or in the left perimeter light, daytime running light, turn signal light and ambient light (E1e26) (ECE vehicles).

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:

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 Model 205.0/1 as of model year 2019, with LED headlamp, with code 460 (Canada version) or code 494 (USA version)

The inner lower left brake light is not actuated if the rear fog light actuation is activated.

IMPORTANT Model 253.9 (except 253.99) as of model year 2020 with code 460 (Canada version)

Model 253.9 (except 253.99) as of model year 2020 with code 494 (US version)

The left taillight is not switched dark by the flasher frequency if standing lights actuation has been activated.

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 sends the "Right turn signal" request (flasher frequency) over the interior CAN to the following control units:

On vehicles with halogen headlamps, the front SAM control unit actuates the right front turn signal light (E2e5) in the right front lamp unit directly.

For model 205, model 253 (except model 253.99) as of 01.06.2019 and model 253.99 (in each case with LED headlamps), the right headlamp control unit receives the flasher frequency and directly actuates the right front turn signal light.

For model 253 (except model 253.99) up to 31.05.2019 with LED headlamps (static), the right headlamp control unit receives the flasher frequency and directly actuates the turn signal light in the right perimeter light, daytime running light and turn signal light (E2e25). For model 253 (except model 253.99) up to 31.05.2019 with LED headlamps (dynamic), the right headlamp control unit receives the flasher frequency and directly actuates the turn signal light in the right perimeter light, daytime running light and turn signal light (except ECE vehicles) or in the right perimeter light, daytime running light, turn signal light and ambient light (E2e26) (ECE vehicles).

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 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 Model 253.9 (except 253.99) as of model year 2020 with code 460 (Canada version)

Model 253.9 (except 253.99) as of model year 2020 with code 494 (US version)

The right taillight is not switched dark by the flasher frequency if standing lights actuation has been activated.

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 activate the "one-touch turn signaling" function, the combination switch must simply be briefly (440 ms) actuated 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.

In addition to the indicator lamps in the instrument cluster, the front SAM control unit directly actuates the indicator lamp in the hazard warning system button (N72/1s57) in the upper control panel control unit (N72/1).

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 of 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 instrument cluster sends the vehicle speed to the front SAM control unit via user interface CAN, electronic ignition lock control unit and interior CAN.

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

Additional function requirement for hazard warning flasher during an emergency stop (with code 23P (Driving Assistance Package)) 

Function sequence for hazard warning flasher during an 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 chassis FlexRay, electronic ignition lock control unit and 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 of 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 is not lower than v = 3 km/h, hazard warning flashing is terminated with cancellation of the "Emergency stop" signal. If the speed drops below the threshold of v = 3 km/h one time, hazard warning flashing continues to be executed regardless of the status of the "Emergency stop" signal.

Hazard warning flashing is then only terminated if the hazard warning system button is actuated with the "Emergency stop" signal not being set or if a speed of 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, the supplemental restraint system control unit (N2/10) sends the crash signal over the user interface CAN, electronic ignition lock control unit and the interior CAN, as well as over 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 CL 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 do so, it sends the status of the CL [ZV] via 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]) or model 205 with code 934 (Taxi emergency alarm system)) 

When an ATA [EDW] alarm or emergency 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.

For model 205 vehicles with code 934 (Taxi emergency alarm system), the special-purpose vehicle multifunction control unit (N26/9) (model 205 with code 965 (Taxi/hire car pre-installation)) transmits the emergency alarm output request via the interior CAN to the front SAM control unit.

Function sequence for PRE-SAFE rear-end turn signaling (with CODE 253 (Rear-end collision warning and protective system)) 

If a vehicle is detected in the area to the rear of the vehicle, and it is deemed to be in an accident-critical position, then the driver of the vehicle in the rear is warned of a possible collision through actuation of the vehicle's rear turn signal lights (except CODE 460 (Canada version) and except CODE 494 (USA version)).

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