Horn switch (41): Connection

The steering wheel buttons are resistive multiplexing and are divided into 2 circuits: Sentronic/horn in one circuit and the other buttons in the other. All buttons are jointly grounded from CIM. The lead for Sentronic/horn is supplied 5V via a CIM-integrated resistor of 560 O. When the horn switch is closed, the lead is grounded and voltage sinks to 0 V. The 2 leads go via coil springs to CIM. CIM transmits the switch status on the bus.