Rear SAM control unit, component description - GF54.21-P-7030RT

MODEL 251.1/0 up to Model Year 8

Fig 1: Identifying Rear SAM Control Unit Component

Courtesy of MERCEDES-BENZ USA

Location

The rear SAM control unit is located in the right rear luggage compartment on the wheelhouse.

General

The rear SAM control unit serves to exchange data and is connected to the Controller Area Network bus Class B (interior) (CAN-B).

Task

The rear SAM control unit reads in the following components, sensors and switches and if necessary control their function illumination and switch and controls illumination.

Controlling

Vent windows
Heated rear window (R1)
Rear exterior lights
Turn signal functions
Central locking of tank cap
Right rear door central locking system
Central locking, rear-end door
Rear-end door power closing
Load compartment illumination
Trailer recognition and trailer illumination
Rear wiper
Anti-theft alarm system (ATA) (with code 551 Anti-theft alarm system (ATA))
Left and right rear door illumination

Reading in and outputting the following signals:

Circuit 30
Circuit 31
Circuit 15
Circuit 54

Reading in following switches, pickups and sensors:

Rear door locking unit (A72)
Fuel level sensor, left half of tank (B4/1)
Fuel level sensor, right half of tank (B4/2)
Right front door rotary tumbler microswitch (M14/5s1)
Left front door rotary tumbler microswitch (M14/6s1)
Left rear door rotary tumbler microswitch (M14/8s1)
Right rear door rotary tumbler microswitch (M14/9s1)
Stop light switch (S9/1)
Engine hood ATA switch (S62)
Rear-end door handle switch (S88/9)
Interference filter 1 (A49/1)
Alarm signal horn with additional battery (H3/1) (for anti-theft alarm system (ATA [EDW]), code 551)
Left vent window obstruction sensor strip (B51/5)
Right vent window obstruction sensor strip (B51/6)

Switching in the following relays:

Socket circuit 15R relay (with run-on) (F4kK)
Heated rear window relay (F4kM)
Rear wiper relay (F4kP)
Trailer circuit 30X relay (F4kL)
Circuit 15R relay (F4kR)
Front passenger seat adjustment comfort relay (K24/2)

The fuel pump relay (F4kO) is located on the load compartment fuse and relay box (F4), but it is actuated by the ME-SFI [ME] control unit (N3/10).

Switching consumers via semiconductor switches

Rear door locking unit
Left taillamp (E3)
Left turn signal lamp (E3e1)
Taillamp and left rear fog lamp (E3e2)
Left backup lamp (E3e3)
Left stop lamp (E3e4)
Right taillamp (E4)
Right turn signal lamp (E4e1)
Taillamp and right rear fog lamp (E4e2)
Right backup lamp (E4e3)
Right stop lamp (E4e4)
Right luggage compartment lamp (E18/4)
Left luggage compartment lamp (E18/5)
Left rear-end door license plate lamp (E19/3)
Right rear-end door license plate lamp (E19/4)
Center high-mounted stop lamp (E21)
Alarm signal horn with additional battery (for anti-theft alarm system (ATA [EDW]), code 551)
Right rear door CL [ZV] motor (M14/9)
fuel filler flap CL [ZV] motor (M14/10)
Left vent window motor (M21/8)
Right vent window motor (M21/9)
Lumbar pump (M25/1)
Overall trailer lighting

with code 494 USA version:

Alarm horn (H3)
Electric Brake Control

Trailer recognition

The rear SAM control unit transmits the information for trailer recognition to the PTS control unit (N62) via CAN-B. If a trailer is shifted into reverse gear or idle. Otherwise, the trailer would be recognized as an obstacle.