Component Description For Rear SAM Control Unit - GF54.21-P-7030LF

Model 217, 222 

Shown on Model 222 before Model year 2018 

Location 

The rear SAM control unit is on the control unit bracket behind the rear pre-fuse box (F33) on the right in the luggage compartment.

Tasks 

Depending on the function sequence the rear SAM control unit supplies various systems and control units with voltage via limit switches. In addition, the rear SAM control unit has the following tasks:

• Reading in of signals 
• Evaluation of input factors 
• Controlling functions 
• Actuation of components 
• Switching of relays 

Reading in of signals 

The input factors are read in via the following connections:

• Direct line 
• Interior CAN (CAN B) 
• Heater LIN (LIN B28) 

Direct line 

The signals from the following components are read via direct lines:

• Trunk lid lock main catch switch (A85/5s1)
• Trunk lock switch safety catch (A85/5s2) (model 222 with code 881 (Remote trunk closing) or code 883 (Power closing function), model 217)
• Rear sun sensor (B32/4)
• Rear window roller sun blind motor (M24) (with code 540 (Electric roller sun blind for rear window))
• Electronic Stability Program control unit (N30/4) (circuit 54)
• Right rear brake wear sensor (S10/4)
• Left rear seat belt buckle switch (S68/11)
• Right rear belt buckle switch (S68/12)
• Center rear seat belt buckle switch (S68/14) (for model 222 without code 224 (Individual rear seat system design))
• Trunk lid external operation switch (S88/8)
• Trunk lid emergency opening switch (S88/10) (with code 494 (USA version))
• Trunk lid control button (S62/26) (with code 881 (Remote trunk closing))

Interior CAN 

The signals are read in by the rear SAM control unit via the interior CAN. The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Heater LIN 

The signals of the following components are read in via heater LIN:

• Rear seat heater control unit (N25/6) (with code 872 (Seat heater in rear))
• Armrest heater control unit (N5) (with code 906 (Front armrest heater) or code 907 (Rear armrest heater))
• AIRSCARF control unit (N25/7) (with code 403 (AIRSCARF system))

Evaluation of input factors 

The input factors are evaluated by the microprocessor and the corresponding components are actuated.

Controlling functions 

The rear SAM control unit controls the following functions:

• Ambient lighting in rear passenger compartment (with code 877 (Ambient lighting))
• Central locking
• Power closing (with code 883 (Power closing), model 217)
• Seat heater in rear (with code 872 (Seat heater in rear))
• Armrest heater (with code 906 (Front armrest heater) or code 907 (Rear armrest heater))

Actuation of components 

The actuation of the components takes place via the following connections:

• Direct line 
• Interior CAN 
• Heater LIN 

Direct line 

The following components are actuated via direct lines:

• Trunk lid lock motor (A85/5m1)
• Left rear lamp unit (E3)
• Inner left rear lamp unit (E3/1) (in model 217)
• Inner left brake light (E3/1e9) (on model 217) (with code 460 (Canada version) or code 494 (USA version) up to model year 2018)
• Left rear side marker light (E3e6) (with code 460 (Canada version) or code 494 (USA version))
• Right rear lamp unit (E4)
• Inner right rear lamp unit (E4/1) (in model 217)
• Inner right brake light (E4/1e9) (on model 217) (with code 460 (Canada version) or code 494 (USA version) up to model year 2018)
• Right rear side marker light (E4e6) (with code 460 (Canada version) or code 494 (USA version))
• Center rear fog light (E7) (without code 460 (Canada version) and without code 494 (USA version))
• Right trunk lamp (E18/4)
• Left trunk lamp (E185)
• Left license plate lamp (E19/1)
• Right license plate lamp (E19/2)
• Center brake lamp (E21)
• Left trunk lid/liftgate ambient lamp and warning lamp (E40/2)
• Right trunk lid/liftgate ambient lamp and warning lamp (E40/3)
• Left rear center console ambient lighting (E43/29) (model 222 up to model year. 2018 with code 877 (Ambient lighting) and code 223 (Electrically adjustable rear bench seat))
• Right rear center console ambient lighting (E43/30) (model 222 up to model year. 2018 with code 877 (Ambient lighting) and code 223 (Electrically adjustable rear bench seat))
• Left rear panel ambient lighting (E43/31) (model 222 up to model year. 2018 with code 877 (Ambient lighting) and code 223 (Electrically adjustable rear bench seat))
• Right rear panel ambient lighting (E43/32) (model 222 up to model year. 2018 with code 877 (Ambient lighting) and code 223 (Electrically adjustable rear bench seat))
• Tank cap central locking actuator (M14/10)
• Glove compartment central locking actuator motor (M14/18) (for model 217.4)
• Stowage compartment central locking actuator motor (M14/19) (for model 217.4)
• Rear window roller sun blind motor (with code 540 (Electric roller sun blind for rear window))
• Rear camera cover motor (M35/2) (model 222 with code 218 (Reversing camera) or code 501 (360° camera), model 217)
• Left rear head restraint release actuator (M53/12) (in model 222 without code 223 (Electrically adjustable rear bench seat), model 217.3)
• Center rear head restraint release actuator (M53/13) (for model 222 without code 223 (Electrically adjustable rear bench seat), model)
• Right rear head restraint release actuator (M53/14) (in model 222 without code 223 (Electrically adjustable rear bench seat), model 217.3)
• Left rear seat active seat belt buckle motor (M64/1) (with code 305 (PRE-SAFE in rear passenger compartment))
• Right rear seat active seat belt buckle motor (M64/2) (with code 305 (PRE-SAFE in rear passenger compartment))
• Ambient lighting power supply (with code 877 (Ambient lighting))

Interior CAN 

The signals are sent by the rear SAM control unit over the interior CAN. The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

Heater LIN 

The following components are actuated via heater LIN:

• Rear seat heater control unit (with code 872 (Seat heater in rear))
• Armrest heater control unit (with code 906 (Front armrest heater) or code 907 (Rear armrest heater))
• AIRSCARF control unit (with code 403 (AIRSCARF system), model 217.4)

Switching of relays 

The following relays are switched by the rear SAM control unit:

• Vehicle interior circuit 15 relay (K40/5kS)
• Rear window heater relay (K40/5kT)
• 2nd seat row cup holder and sockets relay (K40/5kU)
• Relay circuit 15R (K40/5kW) (up to model year. 2018)
• 1st seat row/trunk refrigerator box and sockets relay (K40/5kX)

	Wiring diagram for rear signal acquisition and actuation module (SAM) control unit	Model 217, 222 as of model year 2018	PE54.21-P-2103-97SEC
		Model 217, 222 up to model year 2018 Sheet 1	PE54.21-P-2103-97SEA
		Model 217, 222 up to model year 2018 Sheet 2	PE54.21-P-2103-97SEB