Central Electronic Module (CEM) (2006-2013): Function: Horn
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2013 Volvo C70, 2012 Volvo C70, 2011 Volvo C70, 2010 Volvo C70, and 2009 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.
The horn (16/10-11) is operated when the steering wheel module (SWM) (3/254) receives a signal from the switches in the steering wheel. The steering wheel module (SWM) transmits information via a directly connected cable to the central electronic module (CEM) (4/56) indicating that the switch is closed. The central electronic module (CEM) activates the relay (2/17) for power supply to the horn.