Component Description For Front SAM Control Unit With Fuse And Relay Module - GF54.21-P-6070CA

MODEL 207.3/4 

Location 

The front SAM control unit is located in the left of the engine compartment.

Task 

Two microprocessors are installed in the front SAM control unit, one for control of the basic functions, e.g. the exterior lights, and the second for control of the central gateway functions. Both processors communicate internally with each other over the interior CAN (CAN B) and they can undergo separate diagnosis. The front SAM control unit also has a 3-D acceleration sensor integrated into it, which is used to detect any crash events.

The processor is responsible for the following tasks for controlling the central gateway functions:

• Central gateway (interface CAN) 
• Data container 
• System diagnosis 
• Global variant coding 
• Monitoring CAN bus idle 

The processor is responsible for the following tasks for controlling the basic functions:

• Interior CAN and LIN interface 
• Reading in of sensors and signals 
• Evaluation of input factors 
• Controlling functions 
• Actuation of components 

The fuse and relay module of the front SAM control unit supplies various systems and control units with power through limit switches to match the function sequence.

The following tasks are the responsibility of the fuse and relay module:

• Voltage supply to components 
• Power supply and relay switching 
• Switching consumers using relays 

Detailed information is available in the "Fuse and relay box, as-built configuration" function description.

Central gateway (interface CAN) 

The processor for controlling the central gateway functions also acts as an interface between the following data bus systems:

• Interior CAN
• Diagnostic CAN (CAN D)
• Chassis CAN (CAN E) (up to 31.05.2013)
• Chassis CAN 1 (CAN E1) (as of 01.06.2013)
• Chassis CAN 2 (CAN E2) (as of 01.06.2013)
• Front end CAN (CAN G) (up to 31.05.2013)

Data container 

The data container represents a nonvolatile, mobile data memory and is managed by the processor for controlling the central gateway functions.

Benefits:

During production, data specific to the vehicle, test location and control unit are stored in the data container (e.g. production number, test status, partial tests not completed). These data can be used in the subsequent tests for test sequence control. The total size of the data memory is 128 bytes.

System diagnosis 

The system diagnosis is integrated as a software module in the processor for controlling central gateway functions.

For off-board diagnosis, the following on-board functions are realized by the processor responsible for controlling the central gateway functions:

• CAN line diagnosis
• CAN SPECIFIED/ACTUAL configuration
• Data logger for telediagnosis

Global variant coding 

The processor responsible for controlling the central gateway functions forwards global information such as model series and national version over the various CAN buses to the networked control units. The control units perform part of their configuration process to match this information.

Monitoring CAN bus idle 

The monitoring of the CAN bus idle enables control units to be determined, which keep the CAN bus active at what otherwise is expected to be a CAN bus idle period.

This information is filed in a nonvolatile memory. This in turn serves to ensure that even when the on-board electrical system battery (G1) has been discharged and following a reset of the networked control units, it is still possible to determine whether the discharging of the on-board electrical system battery was caused by the network or by an individual CAN user.

Interior CAN and LIN interface 

The processor for controlling the basic functions also acts as an interface between the following bus systems:

• Instrument panel LIN (LIN 1)
• Wiper/inside rear-view mirror LIN (LIN 2)
• Interior CAN

Reading in of sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Instrument panel LIN 
• Wiper/inside rearview mirror LIN 
• CAN 

Direct line 

The processor for actuating the base functions reads in the signals of the following components over direct lines:

• Refrigerant pressure sensor (B12)
• Outside temperature sensor (B14)
• CDI control unit (N3/9) (hot start signal with diesel engine) (with CODE B03 (ECO start/stop function))
• ME-SFI control unit (N3/10) (hot start signal with gasoline engine) (with CODE B03 (ECO start/stop function))
• Exterior lights switch (S1) (model 207.3 as of 01.06.2010, model 207.4)
• Right front brake wear sensor (S10/2)
• Right rear brake wear sensor (S10/4)
• Brake fluid level switch (S11)
• Parking brake indicator switch (S12)
• Backup lamp switch (S16/2) (for transmission 711, 716)
• Coolant level switch (S41)
• Windshield washer system fluid level switch (S42)
• Right engine hood contact switch (S62/42) (with CODE B03 (ECO start/stop function) and without CODE U60 (Pedestrian protection))

Instrument panel LIN 

The processor for controlling the basic functions reads in the signals from the following components over an instrument panel LIN:

• Upper control panel control unit (N72/1)
• Exterior lights switch (model 207.3 up to 31.05.2010)
• Hazard warning flasher switch (S6/1s1)

Wiper/inside rearview mirror LIN 

The processor responsible for controlling the basic functions reads in the signals from the following components over a wiper/inside rear-view mirror LIN:

• Forward mirror dimming light sensor (A67h1)
• Rearward dimming mirror light sensor (A67h2)
• With CODE 231 (Garage door opener) or CODE 232 (Garage door opener with frequency 284-390 MHz):
  • Garage door opener (A67n2)
• Rain/light sensor (B38/2)

The communication with the processor responsible for controlling the central gateway functions can also send the data read in by the processor responsible for controlling the basic functions to control units that are not connected to the interior CAN.

CAN 

The processor responsible for controlling the basic functions reads in function-relevant data over the interior CAN.

Information from control units that are not connected to the interior CAN are sent by the processor responsible for controlling the central gateway functions over the interior CAN. This can be information from control units which are connected to one or more of the following CANs:

• Diagnostic CAN
• Chassis CAN (up to 31.05.2013)
• Chassis CAN 1 (as of 01.06.2013)
• Chassis CAN 2 (as of 01.06.2013)
• Front end CAN (up to 31.05.2013)

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Evaluation of input factors 

The input factors are evaluated by the processor responsible for controlling the basic functions whereupon the corresponding components are then actuated.

Controlling functions 

The processor responsible for controlling the basic functions manages the following functions:

• ABL
• Interior illumination (IBL)
• Windshield wiper system
• Windshield washer heater (with CODE 875 (Heated windscreen washing system))
• Headlamp cleaning system (with CODE 600 (Headlamp cleaning system))
• Decoupling of on-board electrical system battery and switching-in of additional battery (with CODE B03 (ECO start/stop function))

Actuation of components 

Components are actuated with the following lines:

• Direct line 
• Instrument panel LIN 
• Wiper/inside rearview mirror LIN 

Direct line 

The following components are actuated over direct lines by the processor responsible for controlling the basic functions:

• A/C compressor regulating valve (A9y1) (without CODE B09 (A/C compressor with magnetic clutch))
• A/C compressor regulating valve (A9/7y1) (with CODE B09 (A/C compressor with magnetic clutch))
• A/C compressor magnetic clutch (A9/7y2) (with CODE B09 (A/C compressor with magnetic clutch))
• Left front lamp unit (E1)
• Right front lamp unit (E2)
• Up to 31.05.2013 without CODE 498 (Japan version):
  • Left daytime running lights headlamp (E1/3)
  • Right daytime running lights headlamp (E2/3)
• Up to 31.05.2013 with CODE 498 (Japan version) or without CODE 615 Lamp unit (Bi-xenon headlamp with integral curve illumination) and without CODE 616 (Bi-xenon headlamp unit with integral asymmetrical curve illumination) and without CODE 621 (Intelligent Light System (left-hand traffic)) and without CODE 622 (Intelligent Light System (right-hand traffic)):
  • Left front fog lamp (E5/1)
  • Right front fog lamp (E5/2)
• Up to 31.05.2013 with CODE 460 (Canada version) or CODE 494 (USA version):
  • Left front side marker lamp (E6/1)
  • Right front side marker lamp (E6/2)
• Glove compartment lamp (E13/1) (switched via the glove compartment lamp switch (S17/9))
• Right front footwell lamp (E17/15)
• Left front footwell lamp (E17/16)
• With CODE B03 (ECO start/stop function):
  • Decoupling relay (F32k1)
  • Additional battery relay (K57/2)
• Left horn (H2) and right horn (H2/1)
• Windshield washer system pump (M5/1)
• Headlamp cleaning system pump (M5/2) (with CODE 600 (Headlamp cleaning system))
• Coolant circulation pump (M13/5) (with CODE 581 (Comfort automatic air conditioning))
• Overhead control panel electronics (N70/3)
• Spray nozzle heater (R2/1)
• Spray nozzle hose heater (R2/11) (with CODE 875 (Heated windshield washer system))
• Ashtray illumination (R3e1) (with CODE 301 (Ashtray package/smoker package))
• Exterior lights switch (model 207.3 as of 01.06.2010, model 207.4)
• Front vehicle interior socket (X58/17) (without CODE 301 (Ashtray package/smoker package))

Instrument panel LIN 

The following components are actuated over an instrument panel LIN by the processor responsible for controlling the basic functions:

• Upper control panel control unit
• Exterior lights switch (model 207.3 up to 31.05.2010)
• Hazard warning flasher switch

Wiper/inside rearview mirror LIN 

The following components are actuated over a wiper/inside rear-view mirror-LIN by the processor responsible for controlling the basic functions:

• Inside rear-view mirror (A67)
• Garage door opener (with CODE 232 (Garage door opener with frequency 284-390 MHz) or CODE 231 (Garage door opener))
• Wiper motor (M6/1)

	Wiring diagram for front SAM control unit with fuse and relay module (N10/1)	MODEL 207.3/4Sheet 1	PE54.21-P-2106-97EAA
		MODEL 207.3/4Sheet 2	PE54.21-P-2106-97EAB
		MODEL 207.3/4Sheet 3	PE54.21-P-2106-97EAC
		MODEL 207.3/4Sheet 4	PE54.21-P-2106-97EAD
		MODEL 207.3/4Sheet 5	PE54.21-P-2106-97EAE
		MODEL 207.3/4Sheet 6	PE54.21-P-2106-97EAF
		MODEL 207.3/4Sheet 7	PE54.21-P-2106-97EAG
		MODEL 207.3/4Sheet 8	PE54.21-P-2106-97EAH
		MODEL 207.3/4Sheet 9	PE54.21-P-2106-97EAI