Steering Column Tube Module Control Unit, Component Description - GF54.21-P-6051RR

Model 190 Up To 11/30/18 

Up To Model Year 2019 

Location 

The steering column tube module control unit is located directly underneath the multifunction steering wheel on the steering column tube of the steering column.

Task 

The steering column tube module control unit controls the data exchange between the controls on the multifunction steering wheel 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 via the following connections:

• Direct line 
• Steering LIN (LIN E1) 
• Chassis CAN 1 (CAN E1) 

Direct line 

The steering column tube module control unit reads in the signals from the following components over direct lines:

• Steering wheel angle sensor (N49)
• Combination switch (S4)
• Cruise control lever (S40/4):
  • DISTRONIC control (S40/4r1) (with code 239 (DISTRONIC PLUS))
  • 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 460 (Canada version) and except code 494 (USA version))
• Steering column adjustment switch (S59) (with CODE P64 (Memory package))

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)
• Right multifunction steering wheel button group (S111)
• Steering wheel upshift button (S111/1)

Chassis CAN 1 

The steering column tube module control unit reads in the following signals, among other things, via chassis CAN 1:

• Terminal status of terminal 15
• Status of circuit 58d (switch and controls illumination)

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 lines:

• 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:

• Left multifunction steering wheel button group (symbol illumination)
• Right multifunction steering wheel button group (symbol illumination)

Direct line 

The steering column tube module control unit actuates the SPEEDTRONIC light emitting diode (S40/4v1) (except code 460 (Canada version) and except code 494 (USA version)) via a direct line.

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

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

Wiring diagram for steering column module control unit

PE46.10-P-2101-97HBA