Component Description For Front Sam Control Unit - GF54.21-P-7010FR
Model 257, 290 up to model year 2021
Shown on model 257
Location
The front SAM control unit is located at the left front on the A-pillar.
Tasks
The front SAM control unit has the following tasks:
- Reading in of signals
- Evaluation of input factors
- Controlling functions
- Actuation of components
- Switching of relays
- Sending signals
Reading in of signals
The input factors are read in via the following connections:
- Direct line
- Instrument panel LIN (LIN 1)
- Battery sensor LIN (LIN B15)
- Rain/light sensor LIN (LIN B16)
- Interior CAN (CAN B)
Direct line
The signals from the following components are read via direct lines:
- Outside temperature sensor (B14)
- Supplemental Restraint System control unit (N2/10) (crash signal)
- Powertrain control unit (N127) (Hot start request)
- Hazard warning system button (N72/1s57)
- Voltage dip limiter (R62)
- Exterior lights switch (S1)
- Right front brake wear sensor (S10/2)
- Brake fluid level switch (S11)
- Coolant level switch (S41)
- Windshield washer system fluid level indicator switch (S42)
- Hood contact switch on passenger side (S62/42)
- Hood contact switch on driver's side (S62/43)
- Switch for separate trunk lid lock (S88/6) (with code 887 (Separate trunk lid lock))
Instrument panel LIN
The signals from the following components are read-in over the instrument panel LIN:
- Driver-side instrument panel button group (S6/1) (with code 235 (Parking Pilot with PARKTRONIC) and code 489 (AIR BODY CONTROL) or code 238 (Active Lane Keeping Assist), code 266 (DISTRONIC PLUS with Steering Assist and Stop & Go Pilot), code 463 (Head-up Display) or code 476 (Lane Keeping Assist))
- Analog clock (A70/1)
Battery sensor LIN
The battery sensor (B95) signals are read in over the battery sensor LIN.
Rain and light sensor LIN
The signals from the following components are read in over the rain/light sensor LIN:
- Rain/light sensor with additional functions (B38/2)
- Wiper motor (M6/1)
Interior CAN
The signals are read in by the front SAM control unit via the interior CAN.
The functions that use these signals are described in the individual function descriptions (see the appropriate block diagram or function schematic).
Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.
Controlling functions
The front SAM control unit also controls the following functions:
- Energy management
- Exterior lights (except code 631 (Static LED headlamp, left-hand traffic) and except code 632 (Static LED headlamp, right-hand traffic) and except code P35 (Light package))
- Interior illumination
- Windshield wiper system
Actuation of components
The following components are actuated via direct lines:
- Left front lamp unit (E1) (except code 631 (Static LED headlamp, left-hand traffic) and except code 632 (Static LED headlamp, right-hand traffic) and except code P35 (Light package))
- Right front lamp unit (E2) (except code 631 (Static LED headlamp, left-hand traffic) and except code 632 (Static LED headlamp, right-hand traffic) and except code P35 (Light package))
- Glove compartment lamp (E13/1) over glove compartment lamp switch (S17/9)
- Right front footwell lamp (E17/15) (except code 877 (Ambiance illumination))
- Left front footwell lamp (E17/16) (except code 877 (Ambiance illumination))
- Left front illuminated door sill molding (E17/47) (with code U25 (Door sills with "Mercedes-Benz" lettering, illuminated))
- Right front illuminated door sill molding (E17/48) (with code U25 (Door sills with "Mercedes-Benz" lettering, illuminated))
- Left horn (H2) and right horn (H2/1)
- Windshield washer system pump (M5/1)
- Spray nozzle hose heater (R2/11) (with code 875 (Heated windshield washer system))
The front SAM control unit additionally supplies voltage to the comfort switch and controls illumination, switch illumination (circuit 58d) and ambiance illumination (with code 877 (Ambiance illumination)).
Switching of relays
The following relays are switched by the front SAM control unit:
- Engine compartment circuit 15 relay (K40/8kG)
- Battery disconnect switch relay (K57/4)
Sending signals
The front SAM control unit sends signals via the following connections:
- Instrument panel LIN
- Rain and light sensor LIN
- Interior CAN
Instrument panel LIN
The following components receive signals via the instrument panel LIN:
- Driver-side instrument panel button group (with code 235 (Parking Pilot with PARKTRONIC) and code 489 (AIR BODY CONTROL) or code 238 (Active Lane Keeping Assist), code 266 (DISTRONIC PLUS with Steering Assist and Stop & Go Pilot), code 463 (Head-up Display) or code 476 (Lane Keeping Assist))
- Analog clock
Rain and light sensor LIN
The wiper motor receives signals via the rain/light sensor LIN.
Interior CAN
The signals are sent by the front SAM control unit over the interior CAN.
The functions that use these signals are described in the individual function descriptions (see the appropriate block diagram or function schematic).
| Wiring diagram for front signal acquisition and actuation module (SAM) control unit | PE54.21-P-2114-97XBA |