Steering wheel buttons in manufacturing phase have been covered with soft feel coating.
However, when worn the soft feel coating is dissolving away and creates a sticky film on the buttons.
A simple fix is to scrape off the sticky residue using finger nails.
This will leave a nice smooth button.
There is a subtle color tone change after the sticky layer is taken off, but it is barely noticeable.
Sticky buttons.
After cleaned.
There have been reports that "Goo Gone" is helpful for removing the coating.
However, better try to avoid using solvents, because it is easy to scratch off the original paint also.
It helps to leave the buttons in soap water (e.g., Fairy Washing Up Liquid) overnight. This will make scratching off the sticky part easier.
Buttons in soap water.
Note: Don't try to clean the plastic frame to which the buttons attach. The color layer there is much thinner and too easily comes off along with the sticky coating.
DIY
Remove/install airbag unit on the steering wheel
Risk of injury caused by performing testing or repair work on airbag or emergency tensioning retractor units. Store airbag units with deployment side facing up; do not expose to temperatures greater than 100 °C. When working on these units, disconnect the power supply.
Assessment of airbag and belt tensioner units in accident vehicles
Notes on performing repair, body work and welding on vehicles with airbags and ETR units
Legal requirements on handling and storing airbags and emergency tensioning retractor units
Withdraw ignition key
Remove two screws (arrow). At the same time hold the airbag unit.
Lift off the airbag unit from the steering wheel and detach the plug-in connector from the squib on the gas generator. Installation: Connector must be heard to engage when being plugged in.
Remove airbag unit from steering wheel. Notes on disposing of airbag and emergency tensioning retractor units. Make airbag units unusable.
Install in the reverse order. Installation: The steering wheel must always be replaced after the driver airbag unit has been triggered.
Check the automatic resetting of the combination switch.
Read out fault memory. Connect STAR DIAGNOSIS and read out fault memory.
Bolt, airbag to steering wheel - 8 Nm.
Remove/install steering wheel
32c - Countersunk screw
32 - Steering wheel
A45 - Fanfare horns and airbag clock spring contact
Remove airbag unit from steering wheel (32)
Move steering wheel (32) to horizontal position. Front wheels in straight-ahead position.
Remove steering wheel (32). Do not pay attention to the markings on the upper steering shaft. Installation: The front wheels must be in the straight-ahead position. Fit steering wheel (32) horizontally onto steering shaft. The recesses in the splines (arrows) run vertically.
Check fanfare horns and airbag clock spring contact (A45) for damage. When the steering wheel (32) is detached, the fanfare horns and airbag clock spring contact (A45) must not be twisted, otherwise it will be damaged. Replace damaged fanfare horns and airbag clock spring contact (A45), see: Remove/install clock spring contact.
Install in the reverse order.
Conduct a road test.
Tests during the road test:
Turn signal reset - When the steering wheel is offset by more than 1 tooth, satisfactory resetting of the turn signal is no longer guaranteed.
Airbag indicator lamp - The SRS indicator lamp must not light up on full steering lock in both directions.
Steering wheel position (32) - If the steering wheel (32) is crooked, adjust it by max. 1 tooth.
Bolts, steering wheel to steering shaft - 80 Nm.
Remove/install clock spring contact
32h - Mounting screw
34 - Steering column switch module
A45 - Fanfare horns and airbag clock spring contact
Remove steering wheel
Unscrew a mounting bolt (32h) far enough so that the fanfare horns and airbag clock spring contact (A45) cannot be twisted. The mounting bolts (32h) act as both an anti-rotation device and an assembly aid.
Unscrew remaining mounting bolts (32h) far enough so that the fanfare horns and airbag clock spring contact (A45) detaches from the steering column switch module (34).
Carefully remove fanfare horns and airbag clock spring contact (A45) from steering column switch module (34). Installation: If the fanfare horns and airbag clock spring contact (A45) was twisted, e.g. with steering coupling removed, the center position must be set otherwise the fanfare horns and airbag clock spring contact (A45) will be damaged: Adjust center position of clock spring contact.
Check fanfare horns and airbag clock spring contact (A45) for damage. Do not use oil or grease, as otherwise the function of the fanfare horns and airbag clock spring contact (A45) will be impaired. Perform visual inspection and if necessary replace fanfare horns and airbag clock spring contact (A45).
Install in the reverse order
Set the clock spring contact to center position
The center position of the fanfare horns and airbag clock spring contact (A45) is crucial
for the trouble-free function of the airbag system and signaling system. When removed this is
guaranteed by the screws (32h).
If the fanfare horns and airbag clock spring contact (A45) is nevertheless twisted, e.g. when
the steering coupling is removed or when the screws are unscrewed completely (32h), the
center position of the fanfare horns and airbag (A45) can be adjusted as per the following
work procedure.
Remove fanfare horns and airbag clock spring contact (A45).
Screw the screws (32h) fully into the fanfare horns and airbag clock spring contact (A45).
Turn the fanfare horns and airbag (A45) counterclockwise until a light resistance is detectable (the fanfare horns and airbag clock spring contact (A45) is rolled up completely).
Turn the fanfare horns and airbag clock spring contact (A45) approx. 3 to 3.5 revolutions clockwise (turn back) until the screws (32h) can be unscrewed again through the openings and the fanfare horns and airbag clock spring contact (A45) fixed in the center position. The total adjustment range of the fanfare horns and airbag clock spring contact (A45) is 6 to 7 turns.
Remove/install steering angle sensor
1 - Bolt
N49 - Steering angle sensor
Remove clock spring contact
Unscrew bolt (1)
Remove steering angle sensor (N49) from steering column module.
Install in the reverse order
Remove/install steering column module
1 - Steering column switch module
A45 - Fanfare horns and airbag clock spring contact
N80 - Steering column module
Shown on steering column switch module without voice control system
2 - Cover
3 - Stud bolt
4 - Bolts
N80 - Steering column module
S4 - Combination switch
S40/4 - Cruise control switch with variable speed limiter
S59/1 - Steering column adjustment and easy entry and exit switch group
Remove spiral contact coil (A45)
Remove steering angle sensor
Loosen internal Torx bolt (arrow) and remove steering column switch module (1). Internal Torx bolt (arrow) is secured to prevent it falling out.
Remove cover (2) and remove push button (S40/4) upwards out of steering column tube switch module (1). Installation: Ensure that the studs (3) are seated cleanly in the holes, by paying attention to the guides on the push button (S40).
Remove switch group or switch (S59/1) upwards out of the steering column tube switch module (1).
Installation: Ensure that the studs (3) are seated cleanly in the holes, by paying attention to the guides on the switch group or switch (S59/1).
Remove bolts (4) and remove combination switch (S4) upwards out of steering column switch module (1).
Remove steering column module (N80) upwards out of steering column switch module (1).
Install in the reverse order.
After replacing steering column tube module (N80) on vehicles with code (219) Distronic (DTR) perform initialization of DTR control unit with STAR DIAGNOSIS.