Steering Wheel Module (SWM)
The steering wheel module (SWM) has the task of managing the signals for those functions which can be controlled via the steering wheel control stalks and buttons. The signals are transmitted using LIN communication to the central electronic module (CEM). The central electronic module (CEM) forwards these signals on the controller area network (CAN) to the relevant control modules. The actual functions are not in the steering wheel module (SWM).
The steering wheel module (SWM) manages the control signals for the following functions:
- Volume control and CD track / radio selection
- Volume control during hands free carphone calls and menu selection for the phone module (PHM)
- Menu selection for traffic information
- Front windshield wipers and washers
- Rear windshield wiper and washer
- Cruise control
- Turn signal lamps
- High and low beam
- Trip computer and displaying/erasing text messages in the driver information module (DIM).
The steering wheel module (SWM) is integrated into the steering wheel bracket. The steering wheel must be removed to replace the steering wheel module (SWM). Control stalks, key pads and switches can be replaced as separate units.
Cars with DSTC also have a steering wheel angle sensor in the contact reel in the steering wheel module (SWM).
A simple way to ensure that the steering wheel module (SWM) is powered and grounded is to flash the headlamp high beam or to change the audio or carphone volume.