Turn signal indicator actuation, function - GF82.10-P-3008CA
MODEL 207.3/4 up to model year 2014
Function requirements for turn signal light actuation, general
- No overvoltage or undervoltage (operating voltage range 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 displayed to the driver by actuating the left turn signal indicator lamp (A1e1) or the right turn signal light indicator lamp (A1e2) and the audible turn signal light function check (A1h2) in the instrument cluster (A1). To this end, the instrument cluster receives the flasher frequency sent by the front SAM control unit over the interior CAN. If a turn signal light or turn signal lamp fails, the frequency of the respective turn signal indicator lamp and the acoustic turn signal light function check in the instrument cluster doubles to f = 3 Hz. The flashing frequency of the turn signal lights and turn signal lamps of f = 1.5 Hz remains unchanged.
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 over the 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) directly reads in the position of the combination switch and transmits it to the front SAM control unit via the chassis CAN (CAN E).
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:
- Instrument cluster
- Rear SAM control unit with fuse and relay module (N10/2)
- Trailer recognition control unit (N28/1) (with code (550) Trailer hitch)
- Left front door control unit (N69/1)
The front SAM control unit actuates the left front turn signal light (E1e5) in the left front lamp unit (E1).
The left front door control unit receives the flasher frequency and actuates the left outside mirror turn signal lamp (E6/5).
The rear SAM control unit receives the flasher frequency and actuates the left rear turn signal light (E3e1) in the left rear lamp unit (E3).
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 over the trailer socket (X58).
Function sequence for right turn signal indicator
The right turn signal function is requested by pushing the combination switch upward.
The steering column tube module control unit directly reads in the position of the combination switch and transmits it to the front SAM control unit via the chassis CAN.
The front SAM control unit receives the switch position of the combination switch and sends the "Right turn signal" (flasher frequency) over the interior CAN to the following control units:
- Instrument cluster
- Rear SAM control unit
- Trailer recognition control unit (with code (550) Trailer hitch)
- Right front door control unit (N69/2)
The front SAM control unit actuates the right front turn signal light (E2e5) in the right front lamp unit (E2).
The right front door control unit receives the flasher frequency and actuates the right outside mirror turn signal lamp (E6/6).
The rear SAM control unit receives the flasher frequency and actuates the right rear turn signal light (E4e1).
The trailer recognition control unit receives the flasher frequency and actuates the relevant turn signal light on the trailer via 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 then 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 manual hazard warning flasher is identical to that for turn signaling in terms of signal flow.
However, all the turn signal lights and turn signal lamps on the vehicle are actuated synchronously.
In addition to the displays in the instrument cluster, the indicator lamp in the hazard warning flasher switch (S6/1s1) in the instrument panel switch group (S6/1) is also actuated by the front SAM control unit over 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 %
The hazard warning flasher function comprises the following subfunctions:
- Function sequence for hazard warning flashing, manual
- Function sequence for hazard warning flashing for emergency braking
- Function sequence for hazard warning flashing for airbag deployment
- Function sequence for hazard warning flashing in the event of crash detection
- Function sequence for feedback from locking/unlocking the central locking (CL) (without code (494) USA version and without code (460) Canada version)
- 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 flashing function is activated by pressing the hazard warning flasher switch. The front SAM control unit reads in the status of the hazard warning flasher switch over the instrument panel LIN, and activates the hazard warning flasher by issuing the flasher frequency over the interior CAN. Afterwards all the turn signal lights and turn signal lamps on the vehicle are actuated synchronously.
Additional function requirements for hazard warning flashing for 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 for hazard warning flashing for emergency braking
In the event of emergency braking the Electronic Stability Program control unit (N30/4) (without code (233) DISTRONIC PLUS) or the Premium Electronic Stability Program control unit (N30/7) (with code (233) DISTRONIC PLUS) sends a corresponding signal over the chassis CAN to the front SAM control unit.
If, as a result of emergency braking, the vehicle was decelerated below the speed threshold of v > 3 km/h, the front SAM control unit activates the hazard warning flashing function during emergency braking by outputting the flasher frequency on the interior CAN. All turn signal lights and the turn signal lamps on the vehicle are actuated synchronously.
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 flashing for airbag deployment
- Crash event detected (deceleration a > 4 g)
Function sequence for hazard warning flashing for airbag deployment
If an airbag is triggered, the supplemental restraint system control unit (N2/10) sends the crash signal over the chassis CAN to the front SAM control unit. The front SAM control unit then actuates the hazard warning flashing function by means of outputting the flasher frequency over the interior CAN. Afterwards all the turn signal lights and turn signal lamps on the vehicle are actuated synchronously.
This function is deactivated by pressing the hazard warning flasher switch or by globally unlocking the central locking.
Additional function requirements for hazard warning flashing for crash recognition
- Vehicle deceleration a > 6 g
Function sequence for hazard warning flashing in the event of crash detection
A crash sensor is integrated into the front SAM control unit. If this detects a crash event during a time-out of the supplemental restraint system control unit, the front SAM control unit activates the hazard warning flasher function by outputting the flasher frequency over the interior CAN.
All turn signal lights and the turn signal lamps on the vehicle are actuated synchronously.
This function is deactivated by pressing the hazard warning flasher switch or by globally unlocking the central locking.
Function sequence for feedback from locking/unlocking the CL (without code (494) USA version and without code (460) Canada version)
When the central locking system is locked/unlocked, the electronic ignition lock control unit requests the hazard warning flashing function via the interior CAN. 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.
All turn signal lights and turn signal lamps are actuated at the same time on the vehicle.
All vehicle doors must be closed in order to output the hazard warning flashing function. The trunk lid is assessed as a vehicle door.
Function sequence for ATA flashing (with code (551) Anti-theft alarm system (ATA) [EDW])
If an ATA [EDW] alarm is triggered, the rear SAM control unit requests the hazard warning flasher function over the interior CAN. This request must be sent cyclically so that the flasher frequency results from the bright time and the cycle time.
The front SAM control unit receives this request, and then generates a corresponding flasher frequency which is sent over the interior CAN.
All turn signal lights and the turn signal lamps on the vehicle are actuated synchronously.
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