Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Design





Steering Wheel Buttons







The steering wheel buttons control functions and menu selection for:
- Traffic information (option)
- Audio (option)
- Carphone (option)
- Cruise control (option).

The signals from the steering wheel buttons are transmitted via serial communication.

The steering wheel buttons are connected in series to the steering wheel module (SWM) via contact reel in the steering wheel hub. The steering wheel buttons are connected in the following order, counted from the contact reel:
1. Cruise control
2. Audio/carphone
3. Traffic information.

There are diagnostics for the steering wheel buttons.