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

Model 205 up to Model year 2019 

Model 253 (except 253.99) up to Model year 2020 

Shown on Model 205.0, steering wheel removed 

Courtesy of MERCEDES-BENZ USA

Location 

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

Tasks 

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

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

Reading in of sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Steering LIN (LIN E1) 
• Suspension FlexRay (Flex E) 

Direct line 

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

• Steering wheel angle sensor (N49)
• Combination switch (S4)
• DIRECT SELECT lever (S16/13) (transmission 722, 724, 725)
• 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)
  • SPEEDTRONIC switch (S40/4s6) (except CODE 494 (USA version))
  • DISTRONIC controller (S40/4r1) (with code 239 (Active Distance Assist DISTRONIC) or code 266 (DISTRONIC PLUS with Steer Assist and Stop & Go Pilot))
• Steering column adjustment switch (S59) (with code 275 (Memory package) and except CODE 443 (Steering wheel heater))
• Steering column adjustment and steering wheel heater switch (S59/1) (with CODE 443 (Steering wheel heater))

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:

• Left multifunction steering wheel button group (S110)
• Steering wheel downshift button (S110/1) (transmission 722, 724, 725)
• Right multifunction steering wheel button group (S111)
• Steering wheel upshift button (S111/1) (transmission 722, 724, 725)

Chassis FlexRay 

The steering column tube module control unit reads in, for example, the following signals via the chassis FlexRay:

• Terminal status of terminal 15
• Status of circuit 58d (switch and controls illumination)
• Request to actuate the steering wheel vibration motor (M99) (with CODE 476 (Lane Keeping Assist) or CODE 238 (Active Lane Keeping Assist))

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 relevant components are then actuated.

Actuation of components 

Components are actuated with the following line:

• Steering LIN 
• Direct line 

Steering LIN 

The steering wheel electronics actuates the following components directly. The signals for this are received via the steering LIN from the steering column tube module control unit:

• Multifunction steering wheel button groups (symbol illumination)
• Steering wheel vibration motor (with CODE 476 (Lane Keeping Assist) or CODE 238 (Active Lane Keeping Assist))

Direct line 

The following component is actuated via a direct line:

• SPEEDTRONIC light-emitting diode (S40/4v1) (except CODE 494 (USA version))

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

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

Sending signals 

The steering column tube module control unit sends, for example, the following signals via the chassis FlexRay:

• Steering wheel angle, steering wheel velocity
• Multifunction steering wheel button group status
• Combination switch, status
• Status of steering wheel gearshift buttons (transmission 722, 724, 725)
• Status of DIRECT SELECT lever (transmission 722, 724, 725)
• CRUISE CONTROL lever
• Steering column adjustment switch status (with CODE 275 (Memory package))
• Status of steering wheel heater (with CODE 443 (Steering wheel heater))

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

Wiring diagram for steering column module control unit

PE46.10-P-2101-97FBA