Steering Column Control Module: Description and Operation

GF54.21-P-6051FQ Component Description For Steering Column Tube Module Control Unit
MODEL 218





N80 Steering column module control unit

Location
The steering column tube module control unit is located directly beneath 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 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
^ Evaluating 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)

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 beam 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) (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) (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)
- Downshift steering wheel gearshift button (S110/1)
- Right multifunction steering wheel button group (S111)
- Upshift steering wheel gearshift button (S111/1)

Chassis CAN
The signals are imported by the steering column tube module control unit via the chassis CAN.
The functions resulting therefrom are described in the corresponding 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 via the following lines:
^ Steering LIN
^ Direct line

Steering LIN
The steering wheel electronics then actuates the following components directly, the signals for this are received by it through the steering LIN from the steering column tube module control unit:
- Symbol illumination of the multifunction steering wheel button groups
- Steering wheel vibration motor (M99) (with code (476) Automatic lane detection)

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) (with code (443) Steering wheel heater)
The following components are actuated directly through a looped line by the SRS control unit (N2/10):
- Driver airbag squib 1 (R12/13)
- Driver airbag squib 2 (R12/14)
The following component is actuated through a looped line directly by the steering wheel heater control unit (N25/7) (with code (443) Steering wheel heater):
- Steering wheel heater heating element (R22/4r1)