Component Description For Steering Column Tube Module Control Unit - GF54.21-P-6051RD

Model 172.4 

Illustration shows model 172.4 up to 29.02.2016 

Location 

The steering column tube module control unit is located directly beneath the multifunction steering wheel (MFL) on the steering column tube of the steering column.

Tasks 

The steering column tube module control unit controls the data exchange between the controls on the MFL and the steering column with the corresponding control units that implement the functions.

The steering column tube module control unit has the following tasks:

• Reading in of sensors and signals 
• Evaluation of input factors 
• Actuation of components 

Reading in of sensors and signals 

The input factors are read in over the following connections:

• Direct line 
• Steering LIN (LIN E1) 
• as of 01.03.2016: chassis CAN 1 (CAN E1) 
• up to 29.02.2016: chassis CAN (CAN E) Direct line 

The signals from the following components are read via a direct line:

• Steering wheel angle sensor (N49)
• Combination switch (S4)
• Turn signal lamps switch (S4s1)
• Headlamp flasher and high beams switch (S4s2)
• Low beams switch (S4s3)
• Windshield washer system switch (S4s4)
• Wipe switch (S4s5)
• Cruise control lever (S40/4)
• Resume from memory switch (S40/4s1)
• Decelerate and set switch (S40/4s2)
• Accelerate and set switch (S40/4s3)
• OFF switch (S40/4s4)
• Indicator switch (S40/4s5)
• SPEEDTRONIC switch (S40/4s6) (not with code 494 (USA version) and not with code 498 (Japan version))
• DISTRONIC control (S40/4r1) (with CODE 233 (DISTRONIC PLUS))
• Steering column adjustment switch (S59)
• Steering column adjustment and steering wheel heater switch (S59/1)

Steering LIN 

The steering wheel electronics (N135) directly reads in the signals for the following components and sends them over the steering LIN to the steering column tube module control unit:

• Heating element temperature sensor (R22/4b1)
• Left multifunction steering wheel button group (S110)
• Steering wheel downshift button (S110/1) (with code 428 (Steering wheel shift paddles))
• Right multifunction steering wheel button group (S111)
• Steering wheel upshift button (S111/1) (with code 428 (Steering wheel shift paddles))

Chassis CAN 

The signals are read in by the steering column tube module control unit as of 01.03.2016 via chassis CAN 1 and up to 29.02.2016 via the chassis CAN.

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 that have been read in are evaluated by the integrated microprocessor and the affected components are then actuated.

Actuation of components 

Components are actuated with the following lines:

• Steering LIN 
• Direct line 

Steering LIN 

The steering wheel electronics actuate the symbol illumination of the multifunction steering wheel button groups directly and receives the signals for this from the steering column tube module control unit via the steering LIN.

Direct line 

The following components are actuated via a direct line:

• SPEEDTRONIC LED (S40/4v1) (not with code 494 (USA version) and not with code 498 (Japan version))
• Steering wheel heater indicator lamp (S59/1e1)
• Steering wheel heater heating element (R22/4r1)

The following components are actuated directly via a looped line by the supplemental restraint system control unit (N210):

• Driver airbag squib 1 (R12/13)
• Driver airbag squib 2 (R12/14)

Wiring diagram for steering column module control unit

PE46.10-P-2101-97TAA