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

MODEL 207.3/4 

Illustration shows model 207 up to 31.05.2013 

Illustration shows model 207 as of 01.06.2013 

Location 

The steering column tube module control unit is located directly underneath the multifunction steering wheel (MFL) 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 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 via the following connections:

• Direct line 
• Steering LIN (LIN E1) 
• Chassis CAN (CAN E) (up to 31.05.2013) or chassis CAN 1 (CAN E1) (as of 01.06.2013) 

Direct line 

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

• Steering 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)
• DIRECT SELECT lever (S16/13) (with transmission 722.9 as of 01.06.2013, 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)
  • Indicator switch (S40/4s5)
  • SPEEDTRONIC switch (S40/4s6) (without CODE 494 (USA version) and without CODE 498 (Japan version))
  • DISTRONIC control (S40/4r1) (with CODE 233 (DISTRONIC PLUS))
• Steering column adjustment switch (S59) (without 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:

• Heating element temperature sensor (R22/4b1) (with CODE 443 (Steering wheel heater))
• Left multifunction steering wheel button group (S110)
• Steering wheel downshift button (S110/1) (with transmission 722.9, 725)
• Left horn button (S110s5)
• Right multifunction steering wheel button group (S111)
• Steering wheel upshift button (S111/1) (with transmission 722.9, 725)
• Right horn button (S111s5)

Chassis CAN (up to 31.05.2013) or chassis CAN 1 (as of 01.06.2013) 

The steering column tube module control unit reads in, among others, the following signals via the chassis CAN (up to 31.05.2013) or chassis CAN 1 (as of 01.06.2013):

• Status of engine and drivetrain
• Circuit status
• Switch and controls illumination (circuit 58d)
• Steering wheel heater emergency shutoff
• Request to actuate steering wheel vibration motor (M99)

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 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:

• Symbol illumination of the multifunction steering wheel button groups
• Steering wheel vibration motor (with CODE 476 (Lane Keeping Assist))

Direct line 

The following components are actuated via a direct line:

• SPEEDTRONIC LED (S40/4v1) (not with CODE 494 (USA version) and without CODE 498 (Japan version))
• Steering wheel heater indicator lamp (S59/1e1) (with CODE 443 (Steering wheel heater))
• Steering wheel heater heating element (R22/4r1) (with CODE 443 (Steering wheel heater))

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-2101-97EAA