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

MODEL 218 

Up to 28.02.2013 

As of 01.03.2013 

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.

Tasks 

The steering column tube module control unit is used for data exchange between the control elements on the multifunction steering wheel and the corresponding control units.

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 over the following connections:

• Direct line 
• Steering LIN (LIN E1) 
• Chassis CAN (CAN E) (up to 28.02.2013) or chassis CAN 1 (CAN E1) (as of 01.03.2013) 

Direct line 

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

• 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)
• 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))
  • DISTRONIC control (S40/4r1) (with code 266 (DISTRONIC PLUS with Steering Assist and Stop & Go Pilot))
• 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))
• Heating element temperature sensor (R22/4b1) (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 (with code 443 (Steering wheel heater))
• 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 (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013) 

The steering column tube module control unit also reads in the following signals via the chassis CAN or chassis CAN 1:

• Terminal 15 status
• Status of circuit 58d (switch and controls illumination)
• Status of engine and drivetrain
• Steering wheel heater emergency shutoff (with code 443 (Steering wheel heater))
• Request to actuate 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 

The actuation of the components takes place via the following connections:

• Direct line 
• Steering LIN 

Direct line 

The following components are actuated via direct lines:

• Steering wheel heater heating element (R22/4r1) (as of 01.03.2013 with code 443 (Steering wheel heater))
• SPEEDTRONIC LED (S40/4v1) (without code 494 (USA version))
• Steering wheel heater indicator lamp (S59/1e1) (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)

On vehicles up to 28.02.2013 with CODE 443 (Steering wheel heater), the steering wheel heater control unit (N25/7) actuates the steering wheel heater heating element directly over a connected line.

Steering LIN 

The steering wheel electronics actuate the following components directly. The signals for this are received by the steering wheel electronics 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))

Sending signals 

The steering column tube module control unit sends, for example, the following signals via the chassis CAN (up to 28.02.2013) or chassis CAN 1 (as of 01.03.2013):

• Steering wheel angle, steering wheel velocity
• Multifunction steering wheel button group status
• Combination switch position
• Steering wheel gearshift button status
• Position of DIRECT SELECT lever
• Switch position of cruise control lever
• Steering column adjustment switch status

Wiring diagram for steering column module control unit

PE46.10-P-2101-97XAA